# File lib/sequel/database/schema_methods.rb 896 def primary_key_constraint_sql_fragment(_) 897 'PRIMARY KEY' 898 end
class Sequel::Database
A Database
object represents a virtual connection to a database. The Database
class is meant to be subclassed by database adapters in order to provide the functionality needed for executing queries.
Constants
- OPTS
1 - Methods that execute queries and/or return results
↑ topConstants
- COLUMN_SCHEMA_DATETIME_TYPES
- COLUMN_SCHEMA_STRING_TYPES
Attributes
Whether the schema should be cached for this database. True by default for performance, can be set to false to always issue a database query to get the schema.
The prepared statement object hash for this database, keyed by name symbol
Public Instance Methods
Runs the supplied SQL statement string on the database server. Returns self so it can be safely chained:
DB << "UPDATE albums SET artist_id = NULL" << "DROP TABLE artists"
# File lib/sequel/database/query.rb 25 def <<(sql) 26 run(sql) 27 self 28 end
Call the prepared statement with the given name with the given hash of arguments.
DB[:items].where(id: 1).prepare(:first, :sa) DB.call(:sa) # SELECT * FROM items WHERE id = 1
# File lib/sequel/database/query.rb 35 def call(ps_name, hash=OPTS, &block) 36 prepared_statement(ps_name).call(hash, &block) 37 end
Method that should be used when submitting any DDL (Data Definition Language) SQL, such as create_table
. By default, calls execute_dui
. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 42 def execute_ddl(sql, opts=OPTS, &block) 43 execute_dui(sql, opts, &block) 44 end
Method that should be used when issuing a DELETE or UPDATE statement. By default, calls execute. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 49 def execute_dui(sql, opts=OPTS, &block) 50 execute(sql, opts, &block) 51 end
Method that should be used when issuing a INSERT statement. By default, calls execute_dui. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 56 def execute_insert(sql, opts=OPTS, &block) 57 execute_dui(sql, opts, &block) 58 end
Returns a single value from the database, see Dataset#get.
DB.get(1) # SELECT 1 # => 1 DB.get{server_version.function} # SELECT server_version()
# File lib/sequel/database/query.rb 65 def get(*args, &block) 66 @default_dataset.get(*args, &block) 67 end
Runs the supplied SQL statement string on the database server. Returns nil. Options:
- :server
-
The server to run the SQL on.
DB.run("SET some_server_variable = 42")
# File lib/sequel/database/query.rb 74 def run(sql, opts=OPTS) 75 sql = literal(sql) if sql.is_a?(SQL::PlaceholderLiteralString) 76 execute_ddl(sql, opts) 77 nil 78 end
Returns the schema for the given table as an array with all members being arrays of length 2, the first member being the column name, and the second member being a hash of column information. The table argument can also be a dataset, as long as it only has one table. Available options are:
- :reload
-
Ignore any cached results, and get fresh information from the database.
- :schema
-
An explicit schema to use. It may also be implicitly provided via the table name.
If schema parsing is supported by the database, the column information hash should contain at least the following entries:
- :allow_null
-
Whether NULL is an allowed value for the column.
- :db_type
-
The database type for the column, as a database specific string.
- :default
-
The database default for the column, as a database specific string, or nil if there is no default value.
- :primary_key
-
Whether the columns is a primary key column. If this column is not present, it means that primary key information is unavailable, not that the column is not a primary key.
- :ruby_default
-
The database default for the column, as a ruby object. In many cases, complex database defaults cannot be parsed into ruby objects, in which case nil will be used as the value.
- :type
-
A symbol specifying the type, such as :integer or :string.
Example:
DB.schema(:artists) # [[:id, # {:type=>:integer, # :primary_key=>true, # :default=>"nextval('artist_id_seq'::regclass)", # :ruby_default=>nil, # :db_type=>"integer", # :allow_null=>false}], # [:name, # {:type=>:string, # :primary_key=>false, # :default=>nil, # :ruby_default=>nil, # :db_type=>"text", # :allow_null=>false}]]
# File lib/sequel/database/query.rb 121 def schema(table, opts=OPTS) 122 raise(Error, 'schema parsing is not implemented on this database') unless supports_schema_parsing? 123 124 opts = opts.dup 125 tab = if table.is_a?(Dataset) 126 o = table.opts 127 from = o[:from] 128 raise(Error, "can only parse the schema for a dataset with a single from table") unless from && from.length == 1 && !o.include?(:join) && !o.include?(:sql) 129 table.first_source_table 130 else 131 table 132 end 133 134 qualifiers = split_qualifiers(tab) 135 table_name = qualifiers.pop 136 sch = qualifiers.pop 137 information_schema_schema = case qualifiers.length 138 when 1 139 Sequel.identifier(*qualifiers) 140 when 2 141 Sequel.qualify(*qualifiers) 142 end 143 144 if table.is_a?(Dataset) 145 quoted_name = table.literal(tab) 146 opts[:dataset] = table 147 else 148 quoted_name = schema_utility_dataset.literal(table) 149 end 150 151 opts[:schema] = sch if sch && !opts.include?(:schema) 152 opts[:information_schema_schema] = information_schema_schema if information_schema_schema && !opts.include?(:information_schema_schema) 153 154 Sequel.synchronize{@schemas.delete(quoted_name)} if opts[:reload] 155 if v = Sequel.synchronize{@schemas[quoted_name]} 156 return v 157 end 158 159 cols = schema_parse_table(table_name, opts) 160 raise(Error, "schema parsing returned no columns, table #{table_name.inspect} probably doesn't exist") if cols.nil? || cols.empty? 161 162 primary_keys = 0 163 auto_increment_set = false 164 cols.each do |_,c| 165 auto_increment_set = true if c.has_key?(:auto_increment) 166 primary_keys += 1 if c[:primary_key] 167 end 168 169 cols.each do |_,c| 170 c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type]) unless c.has_key?(:ruby_default) 171 if c[:primary_key] && !auto_increment_set 172 # If adapter didn't set it, assume that integer primary keys are auto incrementing 173 c[:auto_increment] = primary_keys == 1 && !!(c[:db_type] =~ /int/io) 174 end 175 if !c[:max_length] && c[:type] == :string && (max_length = column_schema_max_length(c[:db_type])) 176 c[:max_length] = max_length 177 end 178 end 179 schema_post_process(cols) 180 181 Sequel.synchronize{@schemas[quoted_name] = cols} if cache_schema 182 cols 183 end
Returns true if a table with the given name exists. This requires a query to the database.
DB.table_exists?(:foo) # => false # SELECT NULL FROM foo LIMIT 1
Note that since this does a SELECT from the table, it can give false negatives if you don't have permission to SELECT from the table.
# File lib/sequel/database/query.rb 193 def table_exists?(name) 194 sch, table_name = schema_and_table(name) 195 name = SQL::QualifiedIdentifier.new(sch, table_name) if sch 196 ds = from(name) 197 transaction(:savepoint=>:only){_table_exists?(ds)} 198 true 199 rescue DatabaseError 200 false 201 end
Private Instance Methods
Uncached version of metadata_dataset
, designed for overriding.
# File lib/sequel/database/query.rb 291 def _metadata_dataset 292 dataset 293 end
Should raise an error if the table doesn't not exist, and not raise an error if the table does exist.
# File lib/sequel/database/query.rb 207 def _table_exists?(ds) 208 ds.get(SQL::AliasedExpression.new(Sequel::NULL, :nil)) 209 end
Whether the type should be treated as a string type when parsing the column schema default value.
# File lib/sequel/database/query.rb 213 def column_schema_default_string_type?(type) 214 COLUMN_SCHEMA_STRING_TYPES.include?(type) 215 end
Transform the given normalized default string into a ruby object for the given type.
# File lib/sequel/database/query.rb 219 def column_schema_default_to_ruby_value(default, type) 220 case type 221 when :boolean 222 case default 223 when /[f0]/i 224 false 225 when /[t1]/i 226 true 227 end 228 when :string, :enum, :set, :interval 229 default 230 when :blob 231 Sequel::SQL::Blob.new(default) 232 when :integer 233 Integer(default) 234 when :float 235 Float(default) 236 when :date 237 Sequel.string_to_date(default) 238 when :datetime 239 DateTime.parse(default) 240 when :time 241 Sequel.string_to_time(default) 242 when :decimal 243 BigDecimal(default) 244 end 245 end
Look at the db_type and guess the maximum length of the column. This assumes types such as varchar(255).
# File lib/sequel/database/query.rb 277 def column_schema_max_length(db_type) 278 if db_type =~ /\((\d+)\)/ 279 $1.to_i 280 end 281 end
Normalize the default value string for the given type and return the normalized value.
# File lib/sequel/database/query.rb 249 def column_schema_normalize_default(default, type) 250 if column_schema_default_string_type?(type) 251 return unless m = /\A'(.*)'\z/.match(default) 252 m[1].gsub("''", "'") 253 else 254 default 255 end 256 end
Convert the given default, which should be a database specific string, into a ruby object.
# File lib/sequel/database/query.rb 260 def column_schema_to_ruby_default(default, type) 261 return default unless default.is_a?(String) 262 if COLUMN_SCHEMA_DATETIME_TYPES.include?(type) 263 if /now|today|CURRENT|getdate|\ADate\(\)\z/i.match(default) 264 if type == :date 265 return Sequel::CURRENT_DATE 266 else 267 return Sequel::CURRENT_TIMESTAMP 268 end 269 end 270 end 271 default = column_schema_normalize_default(default, type) 272 column_schema_default_to_ruby_value(default, type) rescue nil 273 end
Return a Method object for the dataset's output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.
# File lib/sequel/database/query.rb 286 def input_identifier_meth(ds=nil) 287 (ds || dataset).method(:input_identifier) 288 end
Return a dataset that uses the default identifier input and output methods for this database. Used when parsing metadata so that column symbols are returned as expected.
# File lib/sequel/database/query.rb 298 def metadata_dataset 299 @metadata_dataset ||= _metadata_dataset 300 end
Return a Method object for the dataset's output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.
# File lib/sequel/database/query.rb 305 def output_identifier_meth(ds=nil) 306 (ds || dataset).method(:output_identifier) 307 end
Remove the cached schema for the given schema name
# File lib/sequel/database/query.rb 310 def remove_cached_schema(table) 311 cache = @default_dataset.send(:cache) 312 Sequel.synchronize{cache.clear} 313 k = quote_schema_table(table) 314 Sequel.synchronize{@schemas.delete(k)} 315 end
Match the database's column type to a ruby type via a regular expression, and return the ruby type as a symbol such as :integer or :string.
# File lib/sequel/database/query.rb 320 def schema_column_type(db_type) 321 case db_type 322 when /\A(character( varying)?|n?(var)?char|n?text|string|clob)/io 323 :string 324 when /\A(int(eger)?|(big|small|tiny)int)/io 325 :integer 326 when /\Adate\z/io 327 :date 328 when /\A((small)?datetime|timestamp(\(\d\))?( with(out)? time zone)?)\z/io 329 :datetime 330 when /\Atime( with(out)? time zone)?\z/io 331 :time 332 when /\A(bool(ean)?)\z/io 333 :boolean 334 when /\A(real|float( unsigned)?|double( precision)?|double\(\d+,\d+\)( unsigned)?)\z/io 335 :float 336 when /\A(?:(?:(?:num(?:ber|eric)?|decimal)(?:\(\d+,\s*(\d+|false|true)\))?))\z/io 337 $1 && ['0', 'false'].include?($1) ? :integer : :decimal 338 when /bytea|blob|image|(var)?binary/io 339 :blob 340 when /\Aenum/io 341 :enum 342 end 343 end
Post process the schema values.
# File lib/sequel/database/query.rb 346 def schema_post_process(cols) 347 # :nocov: 348 if RUBY_VERSION >= '2.5' 349 # :nocov: 350 cols.each do |_, h| 351 db_type = h[:db_type] 352 if db_type.is_a?(String) 353 h[:db_type] = -db_type 354 end 355 end 356 end 357 358 cols.each do |_,c| 359 c.each_value do |val| 360 val.freeze if val.is_a?(String) 361 end 362 end 363 end
2 - Methods that modify the database schema
↑ topConstants
- COLUMN_DEFINITION_ORDER
The order of column modifiers to use when defining a column.
- COMBINABLE_ALTER_TABLE_OPS
The alter table operations that are combinable.
Public Instance Methods
Adds a column to the specified table. This method expects a column name, a datatype and optionally a hash with additional constraints and options:
DB.add_column :items, :name, String, unique: true, null: false DB.add_column :items, :category, String, default: 'ruby'
See alter_table
.
# File lib/sequel/database/schema_methods.rb 25 def add_column(table, *args) 26 alter_table(table) {add_column(*args)} 27 end
Adds an index to a table for the given columns:
DB.add_index :posts, :title DB.add_index :posts, [:author, :title], unique: true
Options:
- :ignore_errors
-
Ignore any DatabaseErrors that are raised
- :name
-
Name to use for index instead of default
See alter_table
.
# File lib/sequel/database/schema_methods.rb 40 def add_index(table, columns, options=OPTS) 41 e = options[:ignore_errors] 42 begin 43 alter_table(table){add_index(columns, options)} 44 rescue DatabaseError 45 raise unless e 46 end 47 nil 48 end
Alters the given table with the specified block. Example:
DB.alter_table :items do add_column :category, String, default: 'ruby' drop_column :category rename_column :cntr, :counter set_column_type :value, Float set_column_default :value, 4.2 add_index [:group, :category] drop_index [:group, :category] end
Note that add_column
accepts all the options available for column definitions using create_table
, and add_index
accepts all the options available for index definition.
See Schema::AlterTableGenerator
and the “Migrations and Schema Modification” guide.
# File lib/sequel/database/schema_methods.rb 67 def alter_table(name, &block) 68 generator = alter_table_generator(&block) 69 remove_cached_schema(name) 70 apply_alter_table_generator(name, generator) 71 nil 72 end
Return a new Schema::AlterTableGenerator instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb 76 def alter_table_generator(&block) 77 alter_table_generator_class.new(self, &block) 78 end
Create a join table using a hash of foreign keys to referenced table names. Example:
create_join_table(cat_id: :cats, dog_id: :dogs) # CREATE TABLE cats_dogs ( # cat_id integer NOT NULL REFERENCES cats, # dog_id integer NOT NULL REFERENCES dogs, # PRIMARY KEY (cat_id, dog_id) # ) # CREATE INDEX cats_dogs_dog_id_cat_id_index ON cats_dogs(dog_id, cat_id)
The primary key and index are used so that almost all operations on the table can benefit from one of the two indexes, and the primary key ensures that entries in the table are unique, which is the typical desire for a join table.
The default table name this will create is the sorted version of the two hash values, joined by an underscore. So the following two method calls create the same table:
create_join_table(cat_id: :cats, dog_id: :dogs) # cats_dogs create_join_table(dog_id: :dogs, cat_id: :cats) # cats_dogs
You can provide column options by making the values in the hash be option hashes, so long as the option hashes have a :table entry giving the table referenced:
create_join_table(cat_id: {table: :cats, type: :Bignum}, dog_id: :dogs)
You can provide a second argument which is a table options hash:
create_join_table({cat_id: :cats, dog_id: :dogs}, temp: true)
Some table options are handled specially:
- :index_options
-
The options to pass to the index
- :name
-
The name of the table to create
- :no_index
-
Set to true not to create the second index.
- :no_primary_key
-
Set to true to not create the primary key.
# File lib/sequel/database/schema_methods.rb 119 def create_join_table(hash, options=OPTS) 120 keys = hash.keys.sort 121 create_table(join_table_name(hash, options), options) do 122 keys.each do |key| 123 v = hash[key] 124 unless v.is_a?(Hash) 125 v = {:table=>v} 126 end 127 v[:null] = false unless v.has_key?(:null) 128 foreign_key(key, v) 129 end 130 primary_key(keys) unless options[:no_primary_key] 131 index(keys.reverse, options[:index_options] || OPTS) unless options[:no_index] 132 end 133 nil 134 end
Forcibly create a join table, attempting to drop it if it already exists, then creating it.
# File lib/sequel/database/schema_methods.rb 137 def create_join_table!(hash, options=OPTS) 138 drop_table?(join_table_name(hash, options)) 139 create_join_table(hash, options) 140 end
Creates the join table unless it already exists.
# File lib/sequel/database/schema_methods.rb 143 def create_join_table?(hash, options=OPTS) 144 if supports_create_table_if_not_exists? && options[:no_index] 145 create_join_table(hash, options.merge(:if_not_exists=>true)) 146 elsif !table_exists?(join_table_name(hash, options)) 147 create_join_table(hash, options) 148 end 149 end
Creates a view, replacing a view with the same name if one already exists.
DB.create_or_replace_view(:some_items, "SELECT * FROM items WHERE price < 100") DB.create_or_replace_view(:some_items, DB[:items].where(category: 'ruby'))
For databases where replacing a view is not natively supported, support is emulated by dropping a view with the same name before creating the view.
# File lib/sequel/database/schema_methods.rb 239 def create_or_replace_view(name, source, options = OPTS) 240 if supports_create_or_replace_view? 241 options = options.merge(:replace=>true) 242 else 243 swallow_database_error{drop_view(name)} 244 end 245 246 create_view(name, source, options) 247 nil 248 end
Creates a table with the columns given in the provided block:
DB.create_table :posts do primary_key :id column :title, String String :content index :title end
General options:
- :as
-
Create the table using the value, which should be either a dataset or a literal SQL string. If this option is used, a block should not be given to the method.
- :ignore_index_errors
-
Ignore any errors when creating indexes.
- :temp
-
Create the table as a temporary table.
MySQL specific options:
- :charset
-
The character set to use for the table.
- :collate
-
The collation to use for the table.
- :engine
-
The table engine to use for the table.
PostgreSQL specific options:
- :on_commit
-
Either :preserve_rows (default), :drop or :delete_rows. Should only be specified when creating a temporary table.
- :foreign
-
Create a foreign table. The value should be the name of the foreign server that was specified in CREATE SERVER.
- :inherits
-
Inherit from a different table. An array can be specified to inherit from multiple tables.
- :unlogged
-
Create the table as an unlogged table.
- :options
-
The OPTIONS clause to use for foreign tables. Should be a hash where keys are option names and values are option values. Note that option names are unquoted, so you should not use untrusted keys.
- :tablespace
-
The tablespace to use for the table.
See Schema::CreateTableGenerator
and the “Schema Modification” guide.
# File lib/sequel/database/schema_methods.rb 187 def create_table(name, options=OPTS, &block) 188 remove_cached_schema(name) 189 if sql = options[:as] 190 raise(Error, "can't provide both :as option and block to create_table") if block 191 create_table_as(name, sql, options) 192 else 193 generator = options[:generator] || create_table_generator(&block) 194 create_table_from_generator(name, generator, options) 195 create_table_indexes_from_generator(name, generator, options) 196 end 197 nil 198 end
Forcibly create a table, attempting to drop it if it already exists, then creating it.
DB.create_table!(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- drop table if already exists # CREATE TABLE a (a integer)
# File lib/sequel/database/schema_methods.rb 206 def create_table!(name, options=OPTS, &block) 207 drop_table?(name) 208 create_table(name, options, &block) 209 end
Creates the table unless the table already exists.
DB.create_table?(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # CREATE TABLE a (a integer) -- if it doesn't already exist
# File lib/sequel/database/schema_methods.rb 216 def create_table?(name, options=OPTS, &block) 217 options = options.dup 218 generator = options[:generator] ||= create_table_generator(&block) 219 if generator.indexes.empty? && supports_create_table_if_not_exists? 220 create_table(name, options.merge!(:if_not_exists=>true)) 221 elsif !table_exists?(name) 222 create_table(name, options) 223 end 224 end
Return a new Schema::CreateTableGenerator instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb 228 def create_table_generator(&block) 229 create_table_generator_class.new(self, &block) 230 end
Creates a view based on a dataset or an SQL string:
DB.create_view(:cheap_items, "SELECT * FROM items WHERE price < 100") # CREATE VIEW cheap_items AS # SELECT * FROM items WHERE price < 100 DB.create_view(:ruby_items, DB[:items].where(category: 'ruby')) # CREATE VIEW ruby_items AS # SELECT * FROM items WHERE (category = 'ruby') DB.create_view(:checked_items, DB[:items].where(:foo), check: true) # CREATE VIEW checked_items AS # SELECT * FROM items WHERE foo # WITH CHECK OPTION
Options:
- :columns
-
The column names to use for the view. If not given, automatically determined based on the input dataset.
- :check
-
Adds a WITH CHECK OPTION clause, so that attempting to modify rows in the underlying table that would not be returned by the view is not allowed. This can be set to :local to use WITH LOCAL CHECK OPTION.
PostgreSQL/SQLite specific option:
- :temp
-
Create a temporary view, automatically dropped on disconnect.
PostgreSQL specific options:
- :materialized
-
Creates a materialized view, similar to a regular view, but backed by a physical table.
- :recursive
-
Creates a recursive view. As columns must be specified for recursive views, you can also set them as the value of this option. Since a recursive view requires a union that isn't in a subquery, if you are providing a Dataset as the source argument, if should probably call the union method with the all: true and from_self: false options.
- :tablespace
-
The tablespace to use for materialized views.
# File lib/sequel/database/schema_methods.rb 286 def create_view(name, source, options = OPTS) 287 execute_ddl(create_view_sql(name, source, options)) 288 remove_cached_schema(name) 289 nil 290 end
Removes a column from the specified table:
DB.drop_column :items, :category
See alter_table
.
# File lib/sequel/database/schema_methods.rb 297 def drop_column(table, *args) 298 alter_table(table) {drop_column(*args)} 299 end
Removes an index for the given table and column(s):
DB.drop_index :posts, :title DB.drop_index :posts, [:author, :title]
See alter_table
.
# File lib/sequel/database/schema_methods.rb 307 def drop_index(table, columns, options=OPTS) 308 alter_table(table){drop_index(columns, options)} 309 end
Drop the join table that would have been created with the same arguments to create_join_table
:
drop_join_table(cat_id: :cats, dog_id: :dogs) # DROP TABLE cats_dogs
# File lib/sequel/database/schema_methods.rb 316 def drop_join_table(hash, options=OPTS) 317 drop_table(join_table_name(hash, options), options) 318 end
Drops one or more tables corresponding to the given names:
DB.drop_table(:posts) # DROP TABLE posts DB.drop_table(:posts, :comments) DB.drop_table(:posts, :comments, cascade: true)
# File lib/sequel/database/schema_methods.rb 325 def drop_table(*names) 326 options = names.last.is_a?(Hash) ? names.pop : OPTS 327 names.each do |n| 328 execute_ddl(drop_table_sql(n, options)) 329 remove_cached_schema(n) 330 end 331 nil 332 end
Drops the table if it already exists. If it doesn't exist, does nothing.
DB.drop_table?(:a) # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- if it already exists
# File lib/sequel/database/schema_methods.rb 340 def drop_table?(*names) 341 options = names.last.is_a?(Hash) ? names.pop : OPTS 342 if supports_drop_table_if_exists? 343 options = options.merge(:if_exists=>true) 344 names.each do |name| 345 drop_table(name, options) 346 end 347 else 348 names.each do |name| 349 drop_table(name, options) if table_exists?(name) 350 end 351 end 352 nil 353 end
Drops one or more views corresponding to the given names:
DB.drop_view(:cheap_items) DB.drop_view(:cheap_items, :pricey_items) DB.drop_view(:cheap_items, :pricey_items, cascade: true) DB.drop_view(:cheap_items, :pricey_items, if_exists: true)
Options:
- :cascade
-
Also drop objects depending on this view.
- :if_exists
-
Do not raise an error if the view does not exist.
PostgreSQL specific options:
- :materialized
-
Drop a materialized view.
# File lib/sequel/database/schema_methods.rb 368 def drop_view(*names) 369 options = names.last.is_a?(Hash) ? names.pop : OPTS 370 names.each do |n| 371 execute_ddl(drop_view_sql(n, options)) 372 remove_cached_schema(n) 373 end 374 nil 375 end
Renames a column in the specified table. This method expects the current column name and the new column name:
DB.rename_column :items, :cntr, :counter
See alter_table
.
# File lib/sequel/database/schema_methods.rb 394 def rename_column(table, *args) 395 alter_table(table) {rename_column(*args)} 396 end
Renames a table:
DB.tables #=> [:items] DB.rename_table :items, :old_items DB.tables #=> [:old_items]
# File lib/sequel/database/schema_methods.rb 382 def rename_table(name, new_name) 383 execute_ddl(rename_table_sql(name, new_name)) 384 remove_cached_schema(name) 385 nil 386 end
Sets the default value for the given column in the given table:
DB.set_column_default :items, :category, 'perl!'
See alter_table
.
# File lib/sequel/database/schema_methods.rb 403 def set_column_default(table, *args) 404 alter_table(table) {set_column_default(*args)} 405 end
Set the data type for the given column in the given table:
DB.set_column_type :items, :price, :float
See alter_table
.
# File lib/sequel/database/schema_methods.rb 412 def set_column_type(table, *args) 413 alter_table(table) {set_column_type(*args)} 414 end
Private Instance Methods
# File lib/sequel/database/schema_methods.rb 452 def alter_table_add_column_sql(table, op) 453 "ADD COLUMN #{column_definition_sql(op)}" 454 end
# File lib/sequel/database/schema_methods.rb 476 def alter_table_add_constraint_sql(table, op) 477 "ADD #{constraint_definition_sql(op)}" 478 end
# File lib/sequel/database/schema_methods.rb 456 def alter_table_drop_column_sql(table, op) 457 "DROP COLUMN #{quote_identifier(op[:name])}#{' CASCADE' if op[:cascade]}" 458 end
# File lib/sequel/database/schema_methods.rb 480 def alter_table_drop_constraint_sql(table, op) 481 quoted_name = quote_identifier(op[:name]) if op[:name] 482 if op[:type] == :foreign_key 483 quoted_name ||= quote_identifier(foreign_key_name(table, op[:columns])) 484 end 485 "DROP CONSTRAINT #{quoted_name}#{' CASCADE' if op[:cascade]}" 486 end
The class used for alter_table
generators.
# File lib/sequel/database/schema_methods.rb 437 def alter_table_generator_class 438 Schema::AlterTableGenerator 439 end
SQL fragment for given alter table operation.
# File lib/sequel/database/schema_methods.rb 442 def alter_table_op_sql(table, op) 443 meth = "alter_table_#{op[:op]}_sql" 444 if respond_to?(meth, true) 445 # Allow calling private methods as alter table op sql methods are private 446 send(meth, table, op) 447 else 448 raise Error, "Unsupported ALTER TABLE operation: #{op[:op]}" 449 end 450 end
# File lib/sequel/database/schema_methods.rb 460 def alter_table_rename_column_sql(table, op) 461 "RENAME COLUMN #{quote_identifier(op[:name])} TO #{quote_identifier(op[:new_name])}" 462 end
# File lib/sequel/database/schema_methods.rb 468 def alter_table_set_column_default_sql(table, op) 469 "ALTER COLUMN #{quote_identifier(op[:name])} SET DEFAULT #{literal(op[:default])}" 470 end
# File lib/sequel/database/schema_methods.rb 472 def alter_table_set_column_null_sql(table, op) 473 "ALTER COLUMN #{quote_identifier(op[:name])} #{op[:null] ? 'DROP' : 'SET'} NOT NULL" 474 end
# File lib/sequel/database/schema_methods.rb 464 def alter_table_set_column_type_sql(table, op) 465 "ALTER COLUMN #{quote_identifier(op[:name])} TYPE #{type_literal(op)}" 466 end
The SQL to execute to modify the table. op should be one of the operations returned by the AlterTableGenerator.
# File lib/sequel/database/schema_methods.rb 490 def alter_table_sql(table, op) 491 case op[:op] 492 when :add_index 493 index_definition_sql(table, op) 494 when :drop_index 495 drop_index_sql(table, op) 496 else 497 if sql = alter_table_op_sql(table, op) 498 "ALTER TABLE #{quote_schema_table(table)} #{sql}" 499 end 500 end 501 end
Array
of SQL statements used to modify the table, corresponding to changes specified by the operations.
# File lib/sequel/database/schema_methods.rb 505 def alter_table_sql_list(table, operations) 506 if supports_combining_alter_table_ops? 507 grouped_ops = [] 508 last_combinable = false 509 operations.each do |op| 510 if combinable_alter_table_op?(op) 511 if sql = alter_table_op_sql(table, op) 512 grouped_ops << [] unless last_combinable 513 grouped_ops.last << sql 514 last_combinable = true 515 end 516 elsif sql = alter_table_sql(table, op) 517 Array(sql).each{|s| grouped_ops << s} 518 last_combinable = false 519 end 520 end 521 grouped_ops.map do |gop| 522 if gop.is_a?(Array) 523 "ALTER TABLE #{quote_schema_table(table)} #{gop.join(', ')}" 524 else 525 gop 526 end 527 end 528 else 529 operations.map{|op| alter_table_sql(table, op)}.flatten.compact 530 end 531 end
Apply the changes in the given alter table ops to the table given by name.
# File lib/sequel/database/schema_methods.rb 419 def apply_alter_table(name, ops) 420 alter_table_sql_list(name, ops).each{|sql| execute_ddl(sql)} 421 end
Apply the operations in the given generator to the table given by name.
# File lib/sequel/database/schema_methods.rb 424 def apply_alter_table_generator(name, generator) 425 ops = generator.operations 426 427 unless can_add_primary_key_constraint_on_nullable_columns? 428 if add_pk = ops.find{|op| op[:op] == :add_constraint && op[:type] == :primary_key} 429 ops = add_pk[:columns].map{|column| {:op => :set_column_null, :name => column, :null => false}} + ops 430 end 431 end 432 433 apply_alter_table(name, ops) 434 end
The SQL string specify the autoincrement property, generally used by primary keys.
# File lib/sequel/database/schema_methods.rb 535 def auto_increment_sql 536 'AUTOINCREMENT' 537 end
Add auto increment SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 553 def column_definition_auto_increment_sql(sql, column) 554 sql << " #{auto_increment_sql}" if column[:auto_increment] 555 end
Add collate SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 558 def column_definition_collate_sql(sql, column) 559 if collate = column[:collate] 560 sql << " COLLATE #{collate}" 561 end 562 end
Add default SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 565 def column_definition_default_sql(sql, column) 566 sql << " DEFAULT #{literal(column[:default])}" if column.include?(:default) 567 end
Add null/not null SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 570 def column_definition_null_sql(sql, column) 571 null = column.fetch(:null, column[:allow_null]) 572 if null.nil? && !can_add_primary_key_constraint_on_nullable_columns? && column[:primary_key] 573 null = false 574 end 575 576 case null 577 when false 578 sql << ' NOT NULL' 579 when true 580 sql << ' NULL' 581 end 582 end
The order of the column definition, as an array of symbols.
# File lib/sequel/database/schema_methods.rb 540 def column_definition_order 541 COLUMN_DEFINITION_ORDER 542 end
Add primary key SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 585 def column_definition_primary_key_sql(sql, column) 586 if column[:primary_key] 587 if name = column[:primary_key_constraint_name] 588 sql << " CONSTRAINT #{quote_identifier(name)}" 589 end 590 sql << " " << primary_key_constraint_sql_fragment(column) 591 constraint_deferrable_sql_append(sql, column[:primary_key_deferrable]) 592 end 593 end
Add foreign key reference SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 596 def column_definition_references_sql(sql, column) 597 if column[:table] 598 if name = column[:foreign_key_constraint_name] 599 sql << " CONSTRAINT #{quote_identifier(name)}" 600 end 601 sql << column_references_column_constraint_sql(column) 602 end 603 end
SQL fragment containing the column creation SQL for the given column.
# File lib/sequel/database/schema_methods.rb 545 def column_definition_sql(column) 546 sql = String.new 547 sql << "#{quote_identifier(column[:name])} #{type_literal(column)}" 548 column_definition_order.each{|m| send(:"column_definition_#{m}_sql", sql, column)} 549 sql 550 end
Add unique constraint SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 606 def column_definition_unique_sql(sql, column) 607 if column[:unique] 608 if name = column[:unique_constraint_name] 609 sql << " CONSTRAINT #{quote_identifier(name)}" 610 end 611 sql << ' ' << unique_constraint_sql_fragment(column) 612 constraint_deferrable_sql_append(sql, column[:unique_deferrable]) 613 end 614 end
SQL for all given columns, used inside a CREATE TABLE block.
# File lib/sequel/database/schema_methods.rb 617 def column_list_sql(generator) 618 (generator.columns.map{|c| column_definition_sql(c)} + generator.constraints.map{|c| constraint_definition_sql(c)}).join(', ') 619 end
SQL fragment for column foreign key references (column constraints)
# File lib/sequel/database/schema_methods.rb 622 def column_references_column_constraint_sql(column) 623 column_references_sql(column) 624 end
SQL fragment for column foreign key references
# File lib/sequel/database/schema_methods.rb 627 def column_references_sql(column) 628 sql = String.new 629 sql << " REFERENCES #{quote_schema_table(column[:table])}" 630 sql << "(#{Array(column[:key]).map{|x| quote_identifier(x)}.join(', ')})" if column[:key] 631 sql << " ON DELETE #{on_delete_clause(column[:on_delete])}" if column[:on_delete] 632 sql << " ON UPDATE #{on_update_clause(column[:on_update])}" if column[:on_update] 633 constraint_deferrable_sql_append(sql, column[:deferrable]) 634 sql 635 end
SQL fragment for table foreign key references (table constraints)
# File lib/sequel/database/schema_methods.rb 638 def column_references_table_constraint_sql(constraint) 639 "FOREIGN KEY #{literal(constraint[:columns])}#{column_references_sql(constraint)}" 640 end
Whether the given alter table operation is combinable.
# File lib/sequel/database/schema_methods.rb 643 def combinable_alter_table_op?(op) 644 COMBINABLE_ALTER_TABLE_OPS.include?(op[:op]) 645 end
SQL fragment specifying the deferrable constraint attributes.
# File lib/sequel/database/schema_methods.rb 672 def constraint_deferrable_sql_append(sql, defer) 673 case defer 674 when nil 675 when false 676 sql << ' NOT DEFERRABLE' 677 when :immediate 678 sql << ' DEFERRABLE INITIALLY IMMEDIATE' 679 else 680 sql << ' DEFERRABLE INITIALLY DEFERRED' 681 end 682 end
SQL fragment specifying a constraint on a table.
# File lib/sequel/database/schema_methods.rb 648 def constraint_definition_sql(constraint) 649 sql = String.new 650 sql << "CONSTRAINT #{quote_identifier(constraint[:name])} " if constraint[:name] 651 case constraint[:type] 652 when :check 653 check = constraint[:check] 654 check = check.first if check.is_a?(Array) && check.length == 1 655 check = filter_expr(check) 656 check = "(#{check})" unless check[0..0] == '(' && check[-1..-1] == ')' 657 sql << "CHECK #{check}" 658 when :primary_key 659 sql << "#{primary_key_constraint_sql_fragment(constraint)} #{literal(constraint[:columns])}" 660 when :foreign_key 661 sql << column_references_table_constraint_sql(constraint.merge(:deferrable=>nil)) 662 when :unique 663 sql << "#{unique_constraint_sql_fragment(constraint)} #{literal(constraint[:columns])}" 664 else 665 raise Error, "Invalid constraint type #{constraint[:type]}, should be :check, :primary_key, :foreign_key, or :unique" 666 end 667 constraint_deferrable_sql_append(sql, constraint[:deferrable]) 668 sql 669 end
Run SQL statement to create the table with the given name from the given SELECT sql statement.
# File lib/sequel/database/schema_methods.rb 742 def create_table_as(name, sql, options) 743 sql = sql.sql if sql.is_a?(Sequel::Dataset) 744 run(create_table_as_sql(name, sql, options)) 745 end
SQL statement for creating a table from the result of a SELECT statement. sql
should be a string representing a SELECT query.
# File lib/sequel/database/schema_methods.rb 749 def create_table_as_sql(name, sql, options) 750 "#{create_table_prefix_sql(name, options)} AS #{sql}" 751 end
Execute the create table statements using the generator.
# File lib/sequel/database/schema_methods.rb 685 def create_table_from_generator(name, generator, options) 686 execute_ddl(create_table_sql(name, generator, options)) 687 end
The class used for create_table
generators.
# File lib/sequel/database/schema_methods.rb 690 def create_table_generator_class 691 Schema::CreateTableGenerator 692 end
Execute the create index statements using the generator.
# File lib/sequel/database/schema_methods.rb 695 def create_table_indexes_from_generator(name, generator, options) 696 e = options[:ignore_index_errors] || options[:if_not_exists] 697 generator.indexes.each do |index| 698 begin 699 pr = proc{index_sql_list(name, [index]).each{|sql| execute_ddl(sql)}} 700 supports_transactional_ddl? ? transaction(:savepoint=>:only, &pr) : pr.call 701 rescue Error 702 raise unless e 703 end 704 end 705 end
SQL fragment for initial part of CREATE TABLE statement
# File lib/sequel/database/schema_methods.rb 754 def create_table_prefix_sql(name, options) 755 "CREATE #{temporary_table_sql if options[:temp]}TABLE#{' IF NOT EXISTS' if options[:if_not_exists]} #{options[:temp] ? quote_identifier(name) : quote_schema_table(name)}" 756 end
SQL statement for creating a table with the given name, columns, and options
# File lib/sequel/database/schema_methods.rb 708 def create_table_sql(name, generator, options) 709 unless supports_named_column_constraints? 710 # Split column constraints into table constraints if they have a name 711 generator.columns.each do |c| 712 if (constraint_name = c.delete(:foreign_key_constraint_name)) && (table = c.delete(:table)) 713 opts = {} 714 opts[:name] = constraint_name 715 [:key, :on_delete, :on_update, :deferrable].each{|k| opts[k] = c[k]} 716 generator.foreign_key([c[:name]], table, opts) 717 end 718 if (constraint_name = c.delete(:unique_constraint_name)) && c.delete(:unique) 719 generator.unique(c[:name], :name=>constraint_name) 720 end 721 if (constraint_name = c.delete(:primary_key_constraint_name)) && c.delete(:primary_key) 722 generator.primary_key([c[:name]], :name=>constraint_name) 723 end 724 end 725 end 726 727 unless can_add_primary_key_constraint_on_nullable_columns? 728 if pk = generator.constraints.find{|op| op[:type] == :primary_key} 729 pk[:columns].each do |column| 730 if matched_column = generator.columns.find{|gc| gc[:name] == column} 731 matched_column[:null] = false 732 end 733 end 734 end 735 end 736 737 "#{create_table_prefix_sql(name, options)} (#{column_list_sql(generator)})" 738 end
SQL fragment for initial part of CREATE VIEW statement
# File lib/sequel/database/schema_methods.rb 759 def create_view_prefix_sql(name, options) 760 create_view_sql_append_columns("CREATE #{'OR REPLACE 'if options[:replace]}VIEW #{quote_schema_table(name)}", options[:columns]) 761 end
SQL statement for creating a view.
# File lib/sequel/database/schema_methods.rb 764 def create_view_sql(name, source, options) 765 source = source.sql if source.is_a?(Dataset) 766 sql = String.new 767 sql << "#{create_view_prefix_sql(name, options)} AS #{source}" 768 if check = options[:check] 769 sql << " WITH#{' LOCAL' if check == :local} CHECK OPTION" 770 end 771 sql 772 end
Append the column list to the SQL, if a column list is given.
# File lib/sequel/database/schema_methods.rb 775 def create_view_sql_append_columns(sql, columns) 776 if columns 777 sql += ' (' 778 schema_utility_dataset.send(:identifier_list_append, sql, columns) 779 sql << ')' 780 end 781 sql 782 end
Default index name for the table and columns, may be too long for certain databases.
# File lib/sequel/database/schema_methods.rb 786 def default_index_name(table_name, columns) 787 schema, table = schema_and_table(table_name) 788 "#{"#{schema}_" if schema}#{table}_#{columns.map{|c| [String, Symbol].any?{|cl| c.is_a?(cl)} ? c : literal(c).gsub(/\W/, '_')}.join('_')}_index" 789 end
The SQL to drop an index for the table.
# File lib/sequel/database/schema_methods.rb 799 def drop_index_sql(table, op) 800 "DROP INDEX #{quote_identifier(op[:name] || default_index_name(table, op[:columns]))}" 801 end
SQL DDL statement to drop the table with the given name.
# File lib/sequel/database/schema_methods.rb 804 def drop_table_sql(name, options) 805 "DROP TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}" 806 end
SQL DDL statement to drop a view with the given name.
# File lib/sequel/database/schema_methods.rb 809 def drop_view_sql(name, options) 810 "DROP VIEW#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}" 811 end
Proxy the filter_expr
call to the dataset, used for creating constraints. Support passing Proc arguments as blocks, as well as treating plain strings as literal strings, so that previous migrations that used this API do not break.
# File lib/sequel/database/schema_methods.rb 816 def filter_expr(arg=nil, &block) 817 if arg.is_a?(Proc) && !block 818 block = arg 819 arg = nil 820 elsif arg.is_a?(String) 821 arg = Sequel.lit(arg) 822 elsif arg.is_a?(Array) 823 if arg.first.is_a?(String) 824 arg = Sequel.lit(*arg) 825 elsif arg.length > 1 826 arg = Sequel.&(*arg) 827 end 828 end 829 schema_utility_dataset.literal(schema_utility_dataset.send(:filter_expr, arg, &block)) 830 end
Get foreign key name for given table and columns.
# File lib/sequel/database/schema_methods.rb 792 def foreign_key_name(table_name, columns) 793 keys = foreign_key_list(table_name).select{|key| key[:columns] == columns} 794 raise(Error, "#{keys.empty? ? 'Missing' : 'Ambiguous'} foreign key for #{columns.inspect}") unless keys.size == 1 795 keys.first[:name] 796 end
SQL statement for creating an index for the table with the given name and index specifications.
# File lib/sequel/database/schema_methods.rb 834 def index_definition_sql(table_name, index) 835 index_name = index[:name] || default_index_name(table_name, index[:columns]) 836 raise Error, "Index types are not supported for this database" if index[:type] 837 raise Error, "Partial indexes are not supported for this database" if index[:where] && !supports_partial_indexes? 838 "CREATE #{'UNIQUE ' if index[:unique]}INDEX #{quote_identifier(index_name)} ON #{quote_schema_table(table_name)} #{literal(index[:columns])}#{" WHERE #{filter_expr(index[:where])}" if index[:where]}" 839 end
Array
of SQL statements, one for each index specification, for the given table.
# File lib/sequel/database/schema_methods.rb 843 def index_sql_list(table_name, indexes) 844 indexes.map{|i| index_definition_sql(table_name, i)} 845 end
Extract the join table name from the arguments given to create_join_table. Also does argument validation for the create_join_table
method.
# File lib/sequel/database/schema_methods.rb 849 def join_table_name(hash, options) 850 entries = hash.values 851 raise Error, "must have 2 entries in hash given to (create|drop)_join_table" unless entries.length == 2 852 if options[:name] 853 options[:name] 854 else 855 table_names = entries.map{|e| join_table_name_extract(e)} 856 table_names.map(&:to_s).sort.join('_') 857 end 858 end
Extract an individual join table name, which should either be a string or symbol, or a hash containing one of those as the value for :table.
# File lib/sequel/database/schema_methods.rb 862 def join_table_name_extract(entry) 863 case entry 864 when Symbol, String 865 entry 866 when Hash 867 join_table_name_extract(entry[:table]) 868 else 869 raise Error, "can't extract table name from #{entry.inspect}" 870 end 871 end
SQL fragment to use for ON DELETE, based on the given action. The following actions are recognized:
- :cascade
-
Delete rows referencing this row.
- :no_action
-
Raise an error if other rows reference this row, allow deferring of the integrity check. This is the default.
- :restrict
-
Raise an error if other rows reference this row, but do not allow deferring the integrity check.
- :set_default
-
Set columns referencing this row to their default value.
- :set_null
-
Set columns referencing this row to NULL.
Any other object given is just converted to a string, with “_” converted to “ ” and upcased.
# File lib/sequel/database/schema_methods.rb 886 def on_delete_clause(action) 887 action.to_s.gsub("_", " ").upcase 888 end
Alias of on_delete_clause
, since the two usually behave the same.
# File lib/sequel/database/schema_methods.rb 891 def on_update_clause(action) 892 on_delete_clause(action) 893 end
Add fragment for primary key specification, separated for easier overridding.
Proxy the quote_schema_table
method to the dataset
# File lib/sequel/database/schema_methods.rb 901 def quote_schema_table(table) 902 schema_utility_dataset.quote_schema_table(table) 903 end
SQL statement for renaming a table.
# File lib/sequel/database/schema_methods.rb 906 def rename_table_sql(name, new_name) 907 "ALTER TABLE #{quote_schema_table(name)} RENAME TO #{quote_schema_table(new_name)}" 908 end
Split the schema information from the table
# File lib/sequel/database/schema_methods.rb 911 def schema_and_table(table_name) 912 schema_utility_dataset.schema_and_table(table_name) 913 end
Return true if the given column schema represents an autoincrementing primary key.
# File lib/sequel/database/schema_methods.rb 916 def schema_autoincrementing_primary_key?(schema) 917 !!(schema[:primary_key] && schema[:auto_increment]) 918 end
The dataset to use for proxying certain schema methods.
# File lib/sequel/database/schema_methods.rb 921 def schema_utility_dataset 922 @default_dataset 923 end
Split the schema information from the table
# File lib/sequel/database/schema_methods.rb 926 def split_qualifiers(table_name) 927 schema_utility_dataset.split_qualifiers(table_name) 928 end
SQL fragment for temporary table
# File lib/sequel/database/schema_methods.rb 931 def temporary_table_sql 932 'TEMPORARY ' 933 end
SQL fragment specifying the type of a given column.
# File lib/sequel/database/schema_methods.rb 936 def type_literal(column) 937 case column[:type] 938 when Class 939 type_literal_generic(column) 940 when :Bignum 941 type_literal_generic_bignum_symbol(column) 942 else 943 type_literal_specific(column) 944 end 945 end
SQL fragment specifying the full type of a column, consider the type with possible modifiers.
# File lib/sequel/database/schema_methods.rb 949 def type_literal_generic(column) 950 meth = "type_literal_generic_#{column[:type].name.to_s.downcase}" 951 if respond_to?(meth, true) 952 # Allow calling private methods as per type literal generic methods are private 953 send(meth, column) 954 else 955 raise Error, "Unsupported ruby class used as database type: #{column[:type]}" 956 end 957 end
Alias for type_literal_generic_numeric
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 960 def type_literal_generic_bigdecimal(column) 961 type_literal_generic_numeric(column) 962 end
Sequel
uses the bigint type by default for :Bignum symbol.
# File lib/sequel/database/schema_methods.rb 965 def type_literal_generic_bignum_symbol(column) 966 :bigint 967 end
Sequel
uses the date type by default for Dates.
# File lib/sequel/database/schema_methods.rb 970 def type_literal_generic_date(column) 971 :date 972 end
Sequel
uses the timestamp type by default for DateTimes.
# File lib/sequel/database/schema_methods.rb 975 def type_literal_generic_datetime(column) 976 :timestamp 977 end
Alias for type_literal_generic_trueclass
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 980 def type_literal_generic_falseclass(column) 981 type_literal_generic_trueclass(column) 982 end
Sequel
uses the blob type by default for Files.
# File lib/sequel/database/schema_methods.rb 985 def type_literal_generic_file(column) 986 :blob 987 end
Alias for type_literal_generic_integer
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 990 def type_literal_generic_fixnum(column) 991 type_literal_generic_integer(column) 992 end
Sequel
uses the double precision type by default for Floats.
# File lib/sequel/database/schema_methods.rb 995 def type_literal_generic_float(column) 996 :"double precision" 997 end
Sequel
uses the integer type by default for integers
# File lib/sequel/database/schema_methods.rb 1000 def type_literal_generic_integer(column) 1001 :integer 1002 end
Sequel
uses the numeric type by default for Numerics and BigDecimals. If a size is given, it is used, otherwise, it will default to whatever the database default is for an unsized value.
# File lib/sequel/database/schema_methods.rb 1007 def type_literal_generic_numeric(column) 1008 column[:size] ? "numeric(#{Array(column[:size]).join(', ')})" : :numeric 1009 end
Use time by default for Time values if :only_time option is used.
# File lib/sequel/database/schema_methods.rb 1036 def type_literal_generic_only_time(column) 1037 :time 1038 end
Sequel
uses the varchar type by default for Strings. If a size isn't present, Sequel
assumes a size of 255. If the :fixed option is used, Sequel
uses the char type. If the :text option is used, Sequel
uses the :text type.
# File lib/sequel/database/schema_methods.rb 1015 def type_literal_generic_string(column) 1016 if column[:text] 1017 uses_clob_for_text? ? :clob : :text 1018 elsif column[:fixed] 1019 "char(#{column[:size]||default_string_column_size})" 1020 else 1021 "varchar(#{column[:size]||default_string_column_size})" 1022 end 1023 end
Sequel
uses the timestamp type by default for Time values. If the :only_time option is used, the time type is used.
# File lib/sequel/database/schema_methods.rb 1027 def type_literal_generic_time(column) 1028 if column[:only_time] 1029 type_literal_generic_only_time(column) 1030 else 1031 type_literal_generic_datetime(column) 1032 end 1033 end
Sequel
uses the boolean type by default for TrueClass
and FalseClass
.
# File lib/sequel/database/schema_methods.rb 1041 def type_literal_generic_trueclass(column) 1042 :boolean 1043 end
SQL fragment for the given type of a column if the column is not one of the generic types specified with a ruby class.
# File lib/sequel/database/schema_methods.rb 1047 def type_literal_specific(column) 1048 type = column[:type] 1049 type = "double precision" if type.to_s == 'double' 1050 column[:size] ||= default_string_column_size if type.to_s == 'varchar' 1051 elements = column[:size] || column[:elements] 1052 "#{type}#{literal(Array(elements)) if elements}#{' UNSIGNED' if column[:unsigned]}" 1053 end
Add fragment for unique specification, separated for easier overridding.
# File lib/sequel/database/schema_methods.rb 1056 def unique_constraint_sql_fragment(_) 1057 'UNIQUE' 1058 end
Whether clob should be used for String
text: true columns.
# File lib/sequel/database/schema_methods.rb 1061 def uses_clob_for_text? 1062 false 1063 end
3 - Methods that create datasets
↑ topPublic Instance Methods
Returns a dataset for the database. If the first argument is a string, the method acts as an alias for Database#fetch
, returning a dataset for arbitrary SQL, with or without placeholders:
DB['SELECT * FROM items'].all DB['SELECT * FROM items WHERE name = ?', my_name].all
Otherwise, acts as an alias for Database#from
, setting the primary table for the dataset:
DB[:items].sql #=> "SELECT * FROM items"
# File lib/sequel/database/dataset.rb 21 def [](*args) 22 args.first.is_a?(String) ? fetch(*args) : from(*args) 23 end
Returns a blank dataset for this database.
DB.dataset # SELECT * DB.dataset.from(:items) # SELECT * FROM items
# File lib/sequel/database/dataset.rb 29 def dataset 30 @dataset_class.new(self) 31 end
Fetches records for an arbitrary SQL statement. If a block is given, it is used to iterate over the records:
DB.fetch('SELECT * FROM items'){|r| p r}
The fetch
method returns a dataset instance:
DB.fetch('SELECT * FROM items').all
fetch
can also perform parameterized queries for protection against SQL injection:
DB.fetch('SELECT * FROM items WHERE name = ?', my_name).all
See caveats listed in Dataset#with_sql regarding datasets using custom SQL and the methods that can be called on them.
# File lib/sequel/database/dataset.rb 49 def fetch(sql, *args, &block) 50 ds = @default_dataset.with_sql(sql, *args) 51 ds.each(&block) if block 52 ds 53 end
Returns a new dataset with the from
method invoked. If a block is given, it acts as a virtual row block
DB.from(:items) # SELECT * FROM items DB.from{schema[:table]} # SELECT * FROM schema.table
# File lib/sequel/database/dataset.rb 60 def from(*args, &block) 61 if block 62 @default_dataset.from(*args, &block) 63 elsif args.length == 1 && (table = args[0]).is_a?(Symbol) 64 @default_dataset.send(:cached_dataset, :"_from_#{table}_ds"){@default_dataset.from(table)} 65 else 66 @default_dataset.from(*args) 67 end 68 end
Returns a new dataset with the select method invoked.
DB.select(1) # SELECT 1 DB.select{server_version.function} # SELECT server_version() DB.select(:id).from(:items) # SELECT id FROM items
# File lib/sequel/database/dataset.rb 75 def select(*args, &block) 76 @default_dataset.select(*args, &block) 77 end
4 - Methods relating to adapters, connecting, disconnecting, and sharding
↑ topConstants
- ADAPTERS
Array
of supported database adapters
Attributes
Public Class Methods
The Database
subclass for the given adapter scheme. Raises Sequel::AdapterNotFound if the adapter could not be loaded.
# File lib/sequel/database/connecting.rb 16 def self.adapter_class(scheme) 17 scheme.is_a?(Class) ? scheme : load_adapter(scheme.to_sym) 18 end
Returns the scheme symbol for the Database
class.
# File lib/sequel/database/connecting.rb 21 def self.adapter_scheme 22 @scheme 23 end
Connects to a database. See Sequel.connect.
# File lib/sequel/database/connecting.rb 26 def self.connect(conn_string, opts = OPTS) 27 case conn_string 28 when String 29 if conn_string.start_with?('jdbc:') 30 c = adapter_class(:jdbc) 31 opts = opts.merge(:orig_opts=>opts.dup) 32 opts = {:uri=>conn_string}.merge!(opts) 33 else 34 uri = URI.parse(conn_string) 35 scheme = uri.scheme 36 c = adapter_class(scheme) 37 uri_options = c.send(:uri_to_options, uri) 38 uri.query.split('&').map{|s| s.split('=')}.each{|k,v| uri_options[k.to_sym] = v if k && !k.empty?} unless uri.query.to_s.strip.empty? 39 uri_options.to_a.each{|k,v| uri_options[k] = URI::DEFAULT_PARSER.unescape(v) if v.is_a?(String)} 40 opts = uri_options.merge(opts).merge!(:orig_opts=>opts.dup, :uri=>conn_string, :adapter=>scheme) 41 end 42 when Hash 43 opts = conn_string.merge(opts) 44 opts = opts.merge(:orig_opts=>opts.dup) 45 c = adapter_class(opts[:adapter_class] || opts[:adapter] || opts['adapter']) 46 else 47 raise Error, "Sequel::Database.connect takes either a Hash or a String, given: #{conn_string.inspect}" 48 end 49 50 opts = opts.inject({}) do |m, (k,v)| 51 k = :user if k.to_s == 'username' 52 m[k.to_sym] = v 53 m 54 end 55 56 begin 57 db = c.new(opts) 58 if block_given? 59 return yield(db) 60 end 61 ensure 62 if block_given? 63 db.disconnect if db 64 Sequel.synchronize{::Sequel::DATABASES.delete(db)} 65 end 66 end 67 db 68 end
Load the adapter from the file system. Raises Sequel::AdapterNotFound if the adapter cannot be loaded, or if the adapter isn't registered correctly after being loaded. Options:
- :map
-
The
Hash
in which to look for an already loaded adapter (defaults to ADAPTER_MAP). - :subdir
-
The subdirectory of sequel/adapters to look in, only to be used for loading subadapters.
# File lib/sequel/database/connecting.rb 76 def self.load_adapter(scheme, opts=OPTS) 77 map = opts[:map] || ADAPTER_MAP 78 if subdir = opts[:subdir] 79 file = "#{subdir}/#{scheme}" 80 else 81 file = scheme 82 end 83 84 unless obj = Sequel.synchronize{map[scheme]} 85 # attempt to load the adapter file 86 begin 87 require "sequel/adapters/#{file}" 88 rescue LoadError => e 89 # If subadapter file doesn't exist, just return, 90 # using the main adapter class without database customizations. 91 return if subdir 92 raise Sequel.convert_exception_class(e, AdapterNotFound) 93 end 94 95 # make sure we actually loaded the adapter 96 unless obj = Sequel.synchronize{map[scheme]} 97 raise AdapterNotFound, "Could not load #{file} adapter: adapter class not registered in ADAPTER_MAP" 98 end 99 end 100 101 obj 102 end
Public Instance Methods
Returns the scheme symbol for this instance's class, which reflects which adapter is being used. In some cases, this can be the same as the database_type
(for native adapters), in others (i.e. adapters with subadapters), it will be different.
Sequel.connect('jdbc:postgres://...').adapter_scheme # => :jdbc
# File lib/sequel/database/connecting.rb 161 def adapter_scheme 162 self.class.adapter_scheme 163 end
Dynamically add new servers or modify server options at runtime. Also adds new servers to the connection pool. Only usable when using a sharded connection pool.
servers argument should be a hash with server name symbol keys and hash or proc values. If a servers key is already in use, it's value is overridden with the value provided.
DB.add_servers(f: {host: "hash_host_f"})
# File lib/sequel/database/connecting.rb 173 def add_servers(servers) 174 unless sharded? 175 raise Error, "cannot call Database#add_servers on a Database instance that does not use a sharded connection pool" 176 end 177 178 h = @opts[:servers] 179 Sequel.synchronize{h.merge!(servers)} 180 @pool.add_servers(servers.keys) 181 end
The database type for this database object, the same as the adapter scheme by default. Should be overridden in adapters (especially shared adapters) to be the correct type, so that even if two separate Database
objects are using different adapters you can tell that they are using the same database type. Even better, you can tell that two Database
objects that are using the same adapter are connecting to different database types.
Sequel.connect('jdbc:postgres://...').database_type # => :postgres
# File lib/sequel/database/connecting.rb 192 def database_type 193 adapter_scheme 194 end
Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected. Options:
- :server
-
Should be a symbol specifing the server to disconnect from,
or an array of symbols to specify multiple servers.
Example:
DB.disconnect # All servers DB.disconnect(server: :server1) # Single server DB.disconnect(server: [:server1, :server2]) # Multiple servers
# File lib/sequel/database/connecting.rb 206 def disconnect(opts = OPTS) 207 pool.disconnect(opts) 208 end
Should only be called by the connection pool code to disconnect a connection. By default, calls the close method on the connection object, since most adapters use that, but should be overwritten on other adapters.
# File lib/sequel/database/connecting.rb 213 def disconnect_connection(conn) 214 conn.close 215 end
Dynamically remove existing servers from the connection pool. Only usable when using a sharded connection pool
servers should be symbols or arrays of symbols. If a nonexistent server is specified, it is ignored. If no servers have been specified for this database, no changes are made. If you attempt to remove the :default server, an error will be raised.
DB.remove_servers(:f1, :f2)
# File lib/sequel/database/connecting.rb 226 def remove_servers(*servers) 227 unless sharded? 228 raise Error, "cannot call Database#remove_servers on a Database instance that does not use a sharded connection pool" 229 end 230 231 h = @opts[:servers] 232 servers.flatten.each{|s| Sequel.synchronize{h.delete(s)}} 233 @pool.remove_servers(servers) 234 end
An array of servers/shards for this Database
object.
DB.servers # Unsharded: => [:default] DB.servers # Sharded: => [:default, :server1, :server2]
# File lib/sequel/database/connecting.rb 240 def servers 241 pool.servers 242 end
Returns true if the database is using a single-threaded connection pool.
# File lib/sequel/database/connecting.rb 245 def single_threaded? 246 @single_threaded 247 end
:nocov:
# File lib/sequel/database/connecting.rb 251 def synchronize(server=nil) 252 @pool.hold(server || :default){|conn| yield conn} 253 end
Attempts to acquire a database connection. Returns true if successful. Will probably raise an Error if unsuccessful. If a server argument is given, attempts to acquire a database connection to the given server/shard.
# File lib/sequel/database/connecting.rb 277 def test_connection(server=nil) 278 synchronize(server){|conn|} 279 true 280 end
Check whether the given connection is currently valid, by running a query against it. If the query fails, the connection should probably be removed from the connection pool.
# File lib/sequel/database/connecting.rb 286 def valid_connection?(conn) 287 sql = valid_connection_sql 288 begin 289 log_connection_execute(conn, sql) 290 rescue Sequel::DatabaseError, *database_error_classes 291 false 292 else 293 true 294 end 295 end
Private Instance Methods
The default options for the connection pool.
# File lib/sequel/database/connecting.rb 300 def connection_pool_default_options 301 {} 302 end
Return the options for the given server by merging the generic options for all server with the specific options for the given server specified in the :servers option.
# File lib/sequel/database/connecting.rb 307 def server_opts(server) 308 opts = if @opts[:servers] and server_options = @opts[:servers][server] 309 case server_options 310 when Hash 311 @opts.merge(server_options) 312 when Proc 313 @opts.merge(server_options.call(self)) 314 else 315 raise Error, 'Server opts should be a hash or proc' 316 end 317 elsif server.is_a?(Hash) 318 @opts.merge(server) 319 else 320 @opts.dup 321 end 322 opts.delete(:servers) 323 opts 324 end
The SQL query to issue to check if a connection is valid.
# File lib/sequel/database/connecting.rb 327 def valid_connection_sql 328 @valid_connection_sql ||= select(nil).sql 329 end
5 - Methods that set defaults for created datasets
↑ topAttributes
The class to use for creating datasets. Should respond to new with the Database
argument as the first argument, and an optional options hash.
Public Instance Methods
If the database has any dataset modules associated with it, use a subclass of the given class that includes the modules as the dataset class.
# File lib/sequel/database/dataset_defaults.rb 18 def dataset_class=(c) 19 unless @dataset_modules.empty? 20 c = Class.new(c) 21 @dataset_modules.each{|m| c.send(:include, m)} 22 end 23 @dataset_class = c 24 reset_default_dataset 25 end
Equivalent to extending all datasets produced by the database with a module. What it actually does is use a subclass of the current dataset_class
as the new dataset_class
, and include the module in the subclass. Instead of a module, you can provide a block that is used to create an anonymous module.
This allows you to override any of the dataset methods even if they are defined directly on the dataset class that this Database
object uses.
If a block is given, a Dataset::DatasetModule instance is created, allowing for the easy creation of named dataset methods that will do caching.
Examples:
# Introspect columns for all of DB's datasets DB.extend_datasets(Sequel::ColumnsIntrospection) # Trace all SELECT queries by printing the SQL and the full backtrace DB.extend_datasets do def fetch_rows(sql) puts sql puts caller super end end # Add some named dataset methods DB.extend_datasets do order :by_id, :id select :with_id_and_name, :id, :name where :active, :active end DB[:table].active.with_id_and_name.by_id # SELECT id, name FROM table WHERE active ORDER BY id
# File lib/sequel/database/dataset_defaults.rb 62 def extend_datasets(mod=nil, &block) 63 raise(Error, "must provide either mod or block, not both") if mod && block 64 mod = Dataset::DatasetModule.new(&block) if block 65 if @dataset_modules.empty? 66 @dataset_modules = [mod] 67 @dataset_class = Class.new(@dataset_class) 68 else 69 @dataset_modules << mod 70 end 71 @dataset_class.send(:include, mod) 72 reset_default_dataset 73 end
Private Instance Methods
The default dataset class to use for the database
# File lib/sequel/database/dataset_defaults.rb 78 def dataset_class_default 79 Sequel::Dataset 80 end
Whether to quote identifiers by default for this database, true by default.
# File lib/sequel/database/dataset_defaults.rb 89 def quote_identifiers_default 90 true 91 end
Reset the default dataset used by most Database
methods that create datasets.
# File lib/sequel/database/dataset_defaults.rb 83 def reset_default_dataset 84 Sequel.synchronize{@symbol_literal_cache.clear} 85 @default_dataset = dataset 86 end
6 - Methods relating to logging
↑ topAttributes
Whether to include information about the connection in use when logging queries.
Numeric
specifying the duration beyond which queries are logged at warn level instead of info level.
Array
of SQL loggers to use for this database.
Log level at which to log SQL queries. This is actually the method sent to the logger, so it should be the method name symbol. The default is :info, it can be set to :debug to log at DEBUG level.
Public Instance Methods
Yield to the block, logging any errors at error level to all loggers, and all other queries with the duration at warn or info level.
# File lib/sequel/database/logging.rb 37 def log_connection_yield(sql, conn, args=nil) 38 return yield if skip_logging? 39 sql = "#{connection_info(conn) if conn && log_connection_info}#{sql}#{"; #{args.inspect}" if args}" 40 timer = Sequel.start_timer 41 42 begin 43 yield 44 rescue => e 45 log_exception(e, sql) 46 raise 47 ensure 48 log_duration(Sequel.elapsed_seconds_since(timer), sql) unless e 49 end 50 end
Log a message at error level, with information about the exception.
# File lib/sequel/database/logging.rb 26 def log_exception(exception, message) 27 log_each(:error, "#{exception.class}: #{exception.message.strip if exception.message}: #{message}") 28 end
Log a message at level info to all loggers.
# File lib/sequel/database/logging.rb 31 def log_info(message, args=nil) 32 log_each(:info, args ? "#{message}; #{args.inspect}" : message) 33 end
Remove any existing loggers and just use the given logger:
DB.logger = Logger.new($stdout)
# File lib/sequel/database/logging.rb 55 def logger=(logger) 56 @loggers = Array(logger) 57 end
Private Instance Methods
String
including information about the connection, for use when logging connection info.
# File lib/sequel/database/logging.rb 69 def connection_info(conn) 70 "(conn: #{conn.__id__}) " 71 end
Log the given SQL and then execute it on the connection, used by the transaction code.
# File lib/sequel/database/logging.rb 75 def log_connection_execute(conn, sql) 76 log_connection_yield(sql, conn){conn.public_send(connection_execute_method, sql)} 77 end
Log message with message prefixed by duration at info level, or warn level if duration is greater than log_warn_duration.
# File lib/sequel/database/logging.rb 81 def log_duration(duration, message) 82 log_each((lwd = log_warn_duration and duration >= lwd) ? :warn : sql_log_level, "(#{sprintf('%0.6fs', duration)}) #{message}") 83 end
Log message at level (which should be :error, :warn, or :info) to all loggers.
# File lib/sequel/database/logging.rb 87 def log_each(level, message) 88 @loggers.each{|logger| logger.public_send(level, message)} 89 end
Determine if logging should be skipped. Defaults to true if no loggers have been specified.
# File lib/sequel/database/logging.rb 63 def skip_logging? 64 @loggers.empty? 65 end
7 - Miscellaneous methods
↑ topConstants
- CHECK_CONSTRAINT_SQLSTATES
- DEFAULT_DATABASE_ERROR_REGEXPS
Empty exception regexp to class map, used by default if
Sequel
doesn't have specific support for the database in use.- DEFAULT_STRING_COLUMN_SIZE
The general default size for string columns for all
Sequel::Database
instances.- EXTENSIONS
Hash
of extension name symbols to callable objects to load the extension into theDatabase
object (usually by extending it with a module defined in the extension).- FOREIGN_KEY_CONSTRAINT_SQLSTATES
- NOT_NULL_CONSTRAINT_SQLSTATES
- SCHEMA_TYPE_CLASSES
Mapping of schema type symbols to class or arrays of classes for that symbol.
- SERIALIZATION_CONSTRAINT_SQLSTATES
- UNIQUE_CONSTRAINT_SQLSTATES
Attributes
The specific default size of string columns for this Sequel::Database
, usually 255 by default.
The options hash for this database
Set the timezone to use for this database, overridding Sequel.database_timezone
.
Public Class Methods
Register a hook that will be run when a new Database
is instantiated. It is called with the new database handle.
# File lib/sequel/database/misc.rb 34 def self.after_initialize(&block) 35 raise Error, "must provide block to after_initialize" unless block 36 Sequel.synchronize do 37 previous = @initialize_hook 38 @initialize_hook = proc do |db| 39 previous.call(db) 40 block.call(db) 41 end 42 end 43 end
Apply an extension to all Database
objects created in the future.
# File lib/sequel/database/misc.rb 46 def self.extension(*extensions) 47 after_initialize{|db| db.extension(*extensions)} 48 end
Constructs a new instance of a database connection with the specified options hash.
Accepts the following options:
- :cache_schema
-
Whether schema should be cached for this
Database
instance - :default_string_column_size
-
The default size of string columns, 255 by default.
- :extensions
-
Extensions to load into this
Database
instance. Can be a symbol, array of symbols, or string with extensions separated by columns. These extensions are loaded after connections are made by the :preconnect option. - :keep_reference
-
Whether to keep a reference to this instance in Sequel::DATABASES, true by default.
- :logger
-
A specific logger to use.
- :loggers
-
An array of loggers to use.
- :log_connection_info
-
Whether connection information should be logged when logging queries.
- :log_warn_duration
-
The number of elapsed seconds after which queries should be logged at warn level.
- :name
-
A name to use for the
Database
object, displayed in PoolTimeout . - :preconnect
-
Automatically create the maximum number of connections, so that they don't need to be created as needed. This is useful when connecting takes a long time and you want to avoid possible latency during runtime. Set to :concurrently to create the connections in separate threads. Otherwise they'll be created sequentially.
- :preconnect_extensions
-
Similar to the :extensions option, but loads the extensions before the connections are made by the :preconnect option.
- :quote_identifiers
-
Whether to quote identifiers.
- :servers
-
A hash specifying a server/shard specific options, keyed by shard symbol .
- :single_threaded
-
Whether to use a single-threaded connection pool.
- :sql_log_level
-
Method to use to log SQL to a logger, :info by default.
All options given are also passed to the connection pool. Additional options respected by the connection pool are :after_connect, :connect_sqls, :max_connections, :pool_timeout, :servers, and :servers_hash. See the connection pool documentation for details.
# File lib/sequel/database/misc.rb 124 def initialize(opts = OPTS) 125 @opts ||= opts 126 @opts = connection_pool_default_options.merge(@opts) 127 @loggers = Array(@opts[:logger]) + Array(@opts[:loggers]) 128 @opts[:servers] = {} if @opts[:servers].is_a?(String) 129 @sharded = !!@opts[:servers] 130 @opts[:adapter_class] = self.class 131 @opts[:single_threaded] = @single_threaded = typecast_value_boolean(@opts.fetch(:single_threaded, Sequel.single_threaded)) 132 @default_string_column_size = @opts[:default_string_column_size] || DEFAULT_STRING_COLUMN_SIZE 133 134 @schemas = {} 135 @prepared_statements = {} 136 @transactions = {} 137 @symbol_literal_cache = {} 138 139 @timezone = nil 140 141 @dataset_class = dataset_class_default 142 @cache_schema = typecast_value_boolean(@opts.fetch(:cache_schema, true)) 143 @dataset_modules = [] 144 @loaded_extensions = [] 145 @schema_type_classes = SCHEMA_TYPE_CLASSES.dup 146 147 self.sql_log_level = @opts[:sql_log_level] ? @opts[:sql_log_level].to_sym : :info 148 self.log_warn_duration = @opts[:log_warn_duration] 149 self.log_connection_info = typecast_value_boolean(@opts[:log_connection_info]) 150 151 @pool = ConnectionPool.get_pool(self, @opts) 152 153 reset_default_dataset 154 adapter_initialize 155 156 keep_reference = typecast_value_boolean(@opts[:keep_reference]) != false 157 begin 158 Sequel.synchronize{::Sequel::DATABASES.push(self)} if keep_reference 159 Sequel::Database.run_after_initialize(self) 160 161 initialize_load_extensions(:preconnect_extensions) 162 163 if typecast_value_boolean(@opts[:preconnect]) && @pool.respond_to?(:preconnect, true) 164 concurrent = typecast_value_string(@opts[:preconnect]) == "concurrently" 165 @pool.send(:preconnect, concurrent) 166 end 167 168 initialize_load_extensions(:extensions) 169 test_connection if typecast_value_boolean(@opts.fetch(:test, true)) && respond_to?(:connect, true) 170 rescue 171 Sequel.synchronize{::Sequel::DATABASES.delete(self)} if keep_reference 172 raise 173 end 174 end
Register an extension callback for Database
objects. ext should be the extension name symbol, and mod should either be a Module that the database is extended with, or a callable object called with the database object. If mod is not provided, a block can be provided and is treated as the mod object.
# File lib/sequel/database/misc.rb 55 def self.register_extension(ext, mod=nil, &block) 56 if mod 57 raise(Error, "cannot provide both mod and block to Database.register_extension") if block 58 if mod.is_a?(Module) 59 block = proc{|db| db.extend(mod)} 60 else 61 block = mod 62 end 63 end 64 Sequel.synchronize{EXTENSIONS[ext] = block} 65 end
Run the after_initialize
hook for the given instance
.
# File lib/sequel/database/misc.rb 68 def self.run_after_initialize(instance) 69 @initialize_hook.call(instance) 70 end
Private Class Methods
Converts a uri to an options hash. These options are then passed to a newly created database object.
# File lib/sequel/database/misc.rb 74 def self.uri_to_options(uri) 75 { 76 :user => uri.user, 77 :password => uri.password, 78 :port => uri.port, 79 :host => uri.hostname, 80 :database => (m = /\/(.*)/.match(uri.path)) && (m[1]) 81 } 82 end
Public Instance Methods
Cast the given type to a literal type
DB.cast_type_literal(Float) # double precision DB.cast_type_literal(:foo) # foo
# File lib/sequel/database/misc.rb 203 def cast_type_literal(type) 204 type_literal(:type=>type) 205 end
Load an extension into the receiver. In addition to requiring the extension file, this also modifies the database to work with the extension (usually extending it with a module defined in the extension file). If no related extension file exists or the extension does not have specific support for Database
objects, an Error will be raised. Returns self.
# File lib/sequel/database/misc.rb 212 def extension(*exts) 213 Sequel.extension(*exts) 214 exts.each do |ext| 215 if pr = Sequel.synchronize{EXTENSIONS[ext]} 216 unless Sequel.synchronize{@loaded_extensions.include?(ext)} 217 Sequel.synchronize{@loaded_extensions << ext} 218 pr.call(self) 219 end 220 else 221 raise(Error, "Extension #{ext} does not have specific support handling individual databases (try: Sequel.extension #{ext.inspect})") 222 end 223 end 224 self 225 end
Freeze internal data structures for the Database
instance.
# File lib/sequel/database/misc.rb 177 def freeze 178 valid_connection_sql 179 metadata_dataset 180 @opts.freeze 181 @loggers.freeze 182 @pool.freeze 183 @dataset_class.freeze 184 @dataset_modules.freeze 185 @schema_type_classes.freeze 186 @loaded_extensions.freeze 187 metadata_dataset 188 super 189 end
Convert the given timestamp from the application's timezone, to the databases's timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb 230 def from_application_timestamp(v) 231 Sequel.convert_output_timestamp(v, timezone) 232 end
Returns a string representation of the database object including the class name and connection URI and options used when connecting (if any).
# File lib/sequel/database/misc.rb 236 def inspect 237 a = [] 238 a << uri.inspect if uri 239 if (oo = opts[:orig_opts]) && !oo.empty? 240 a << oo.inspect 241 end 242 "#<#{self.class}: #{a.join(' ')}>" 243 end
Proxy the literal call to the dataset.
DB.literal(1) # 1 DB.literal(:a) # a DB.literal('a') # 'a'
# File lib/sequel/database/misc.rb 250 def literal(v) 251 schema_utility_dataset.literal(v) 252 end
Return the literalized version of the symbol if cached, or nil if it is not cached.
# File lib/sequel/database/misc.rb 256 def literal_symbol(sym) 257 Sequel.synchronize{@symbol_literal_cache[sym]} 258 end
Set the cached value of the literal symbol.
# File lib/sequel/database/misc.rb 261 def literal_symbol_set(sym, lit) 262 Sequel.synchronize{@symbol_literal_cache[sym] = lit} 263 end
Synchronize access to the prepared statements cache.
# File lib/sequel/database/misc.rb 266 def prepared_statement(name) 267 Sequel.synchronize{prepared_statements[name]} 268 end
Proxy the quote_identifier
method to the dataset, useful for quoting unqualified identifiers for use outside of datasets.
# File lib/sequel/database/misc.rb 273 def quote_identifier(v) 274 schema_utility_dataset.quote_identifier(v) 275 end
Return ruby class or array of classes for the given type symbol.
# File lib/sequel/database/misc.rb 278 def schema_type_class(type) 279 @schema_type_classes[type] 280 end
Default serial primary key options, used by the table creation code.
# File lib/sequel/database/misc.rb 283 def serial_primary_key_options 284 {:primary_key => true, :type => Integer, :auto_increment => true} 285 end
Cache the prepared statement object at the given name.
# File lib/sequel/database/misc.rb 288 def set_prepared_statement(name, ps) 289 Sequel.synchronize{prepared_statements[name] = ps} 290 end
Whether this database instance uses multiple servers, either for sharding or for primary/replica configurations.
# File lib/sequel/database/misc.rb 294 def sharded? 295 @sharded 296 end
The timezone to use for this database, defaulting to Sequel.database_timezone
.
# File lib/sequel/database/misc.rb 299 def timezone 300 @timezone || Sequel.database_timezone 301 end
Convert the given timestamp to the application's timezone, from the databases's timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb 306 def to_application_timestamp(v) 307 Sequel.convert_timestamp(v, timezone) 308 end
Typecast the value to the given column_type. Calls typecast_value_#{column_type} if the method exists, otherwise returns the value. This method should raise Sequel::InvalidValue if assigned value is invalid.
# File lib/sequel/database/misc.rb 315 def typecast_value(column_type, value) 316 return nil if value.nil? 317 meth = "typecast_value_#{column_type}" 318 begin 319 # Allow calling private methods as per-type typecasting methods are private 320 respond_to?(meth, true) ? send(meth, value) : value 321 rescue ArgumentError, TypeError => e 322 raise Sequel.convert_exception_class(e, InvalidValue) 323 end 324 end
Returns the URI use to connect to the database. If a URI was not used when connecting, returns nil.
# File lib/sequel/database/misc.rb 328 def uri 329 opts[:uri] 330 end
Explicit alias of uri for easier subclassing.
# File lib/sequel/database/misc.rb 333 def url 334 uri 335 end
Private Instance Methods
:nocov:
# File lib/sequel/database/misc.rb 504 def _typecast_value_string_to_decimal(value) 505 d = BigDecimal(value) 506 if d.zero? 507 # BigDecimal parsing is loose by default, returning a 0 value for 508 # invalid input. If a zero value is received, use Float to check 509 # for validity. 510 begin 511 Float(value) 512 rescue ArgumentError 513 raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}" 514 end 515 end 516 d 517 end
Per adapter initialization method, empty by default.
# File lib/sequel/database/misc.rb 340 def adapter_initialize 341 end
Returns true when the object is considered blank. The only objects that are blank are nil, false, strings with all whitespace, and ones that respond true to empty?
# File lib/sequel/database/misc.rb 347 def blank_object?(obj) 348 return obj.blank? if obj.respond_to?(:blank?) 349 case obj 350 when NilClass, FalseClass 351 true 352 when Numeric, TrueClass 353 false 354 when String 355 obj.strip.empty? 356 else 357 obj.respond_to?(:empty?) ? obj.empty? : false 358 end 359 end
Return the Sequel::DatabaseError
subclass to wrap the given exception in.
# File lib/sequel/database/misc.rb 370 def database_error_class(exception, opts) 371 database_specific_error_class(exception, opts) || DatabaseError 372 end
An enumerable yielding pairs of regexps and exception classes, used to match against underlying driver exception messages in order to raise a more specific Sequel::DatabaseError
subclass.
# File lib/sequel/database/misc.rb 364 def database_error_regexps 365 DEFAULT_DATABASE_ERROR_REGEXPS 366 end
Return the SQLState for the given exception, if one can be determined
# File lib/sequel/database/misc.rb 375 def database_exception_sqlstate(exception, opts) 376 nil 377 end
Return a specific Sequel::DatabaseError
exception class if one is appropriate for the underlying exception, or nil if there is no specific exception class.
# File lib/sequel/database/misc.rb 382 def database_specific_error_class(exception, opts) 383 return DatabaseDisconnectError if disconnect_error?(exception, opts) 384 385 if sqlstate = database_exception_sqlstate(exception, opts) 386 if klass = database_specific_error_class_from_sqlstate(sqlstate) 387 return klass 388 end 389 else 390 database_error_regexps.each do |regexp, klss| 391 return klss if exception.message =~ regexp 392 end 393 end 394 395 nil 396 end
Given the SQLState, return the appropriate DatabaseError subclass.
# File lib/sequel/database/misc.rb 404 def database_specific_error_class_from_sqlstate(sqlstate) 405 case sqlstate 406 when *NOT_NULL_CONSTRAINT_SQLSTATES 407 NotNullConstraintViolation 408 when *FOREIGN_KEY_CONSTRAINT_SQLSTATES 409 ForeignKeyConstraintViolation 410 when *UNIQUE_CONSTRAINT_SQLSTATES 411 UniqueConstraintViolation 412 when *CHECK_CONSTRAINT_SQLSTATES 413 CheckConstraintViolation 414 when *SERIALIZATION_CONSTRAINT_SQLSTATES 415 SerializationFailure 416 end 417 end
Return true if exception represents a disconnect error, false otherwise.
# File lib/sequel/database/misc.rb 420 def disconnect_error?(exception, opts) 421 opts[:disconnect] 422 end
Load extensions during initialization from the given key in opts.
# File lib/sequel/database/misc.rb 425 def initialize_load_extensions(key) 426 case exts = @opts[key] 427 when String 428 extension(*exts.split(',').map(&:to_sym)) 429 when Array 430 extension(*exts) 431 when Symbol 432 extension(exts) 433 when nil 434 # nothing 435 else 436 raise Error, "unsupported Database #{key.inspect} option: #{@opts[key].inspect}" 437 end 438 end
Convert the given exception to an appropriate Sequel::DatabaseError
subclass, keeping message and backtrace.
# File lib/sequel/database/misc.rb 442 def raise_error(exception, opts=OPTS) 443 if !opts[:classes] || Array(opts[:classes]).any?{|c| exception.is_a?(c)} 444 raise Sequel.convert_exception_class(exception, database_error_class(exception, opts)) 445 else 446 raise exception 447 end 448 end
Swallow database errors, unless they are connect/disconnect errors.
# File lib/sequel/database/misc.rb 451 def swallow_database_error 452 yield 453 rescue Sequel::DatabaseDisconnectError, DatabaseConnectionError 454 # Always raise disconnect errors 455 raise 456 rescue Sequel::DatabaseError 457 # Don't raise other database errors. 458 nil 459 # else 460 # Don't rescue other exceptions, they will be raised normally. 461 end
Typecast the value to an SQL::Blob
# File lib/sequel/database/misc.rb 464 def typecast_value_blob(value) 465 value.is_a?(Sequel::SQL::Blob) ? value : Sequel::SQL::Blob.new(value) 466 end
Typecast the value to true, false, or nil
# File lib/sequel/database/misc.rb 469 def typecast_value_boolean(value) 470 case value 471 when false, 0, "0", /\Af(alse)?\z/i, /\Ano?\z/i 472 false 473 else 474 blank_object?(value) ? nil : true 475 end 476 end
Typecast the value to a Date
# File lib/sequel/database/misc.rb 479 def typecast_value_date(value) 480 case value 481 when DateTime, Time 482 Date.new(value.year, value.month, value.day) 483 when Date 484 value 485 when String 486 Sequel.string_to_date(value) 487 when Hash 488 Date.new(*[:year, :month, :day].map{|x| (value[x] || value[x.to_s]).to_i}) 489 else 490 raise InvalidValue, "invalid value for Date: #{value.inspect}" 491 end 492 end
Typecast the value to a DateTime or Time depending on Sequel.datetime_class
# File lib/sequel/database/misc.rb 495 def typecast_value_datetime(value) 496 Sequel.typecast_to_application_timestamp(value) 497 end
Typecast the value to a BigDecimal
# File lib/sequel/database/misc.rb 522 def typecast_value_decimal(value) 523 case value 524 when BigDecimal 525 value 526 when Numeric 527 BigDecimal(value.to_s) 528 when String 529 _typecast_value_string_to_decimal(value) 530 else 531 raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}" 532 end 533 end
Typecast the value to an Integer
# File lib/sequel/database/misc.rb 539 def typecast_value_integer(value) 540 (value.is_a?(String) && value =~ /\A0+(\d)/) ? Integer(value, 10) : Integer(value) 541 end
Typecast the value to a String
# File lib/sequel/database/misc.rb 544 def typecast_value_string(value) 545 case value 546 when Hash, Array 547 raise Sequel::InvalidValue, "invalid value for String: #{value.inspect}" 548 else 549 value.to_s 550 end 551 end
Typecast the value to a Time
# File lib/sequel/database/misc.rb 554 def typecast_value_time(value) 555 case value 556 when Time 557 if value.is_a?(SQLTime) 558 value 559 else 560 SQLTime.create(value.hour, value.min, value.sec, value.nsec/1000.0) 561 end 562 when String 563 Sequel.string_to_time(value) 564 when Hash 565 SQLTime.create(*[:hour, :minute, :second].map{|x| (value[x] || value[x.to_s]).to_i}) 566 else 567 raise Sequel::InvalidValue, "invalid value for Time: #{value.inspect}" 568 end 569 end
9 - Methods that describe what the database supports
↑ topPublic Instance Methods
Whether the database uses a global namespace for the index, true by default. If false, the indexes are going to be namespaced per table.
# File lib/sequel/database/features.rb 13 def global_index_namespace? 14 true 15 end
Whether the database supports CREATE TABLE IF NOT EXISTS syntax, false by default.
# File lib/sequel/database/features.rb 19 def supports_create_table_if_not_exists? 20 false 21 end
Whether the database supports deferrable constraints, false by default as few databases do.
# File lib/sequel/database/features.rb 25 def supports_deferrable_constraints? 26 false 27 end
Whether the database supports deferrable foreign key constraints, false by default as few databases do.
# File lib/sequel/database/features.rb 31 def supports_deferrable_foreign_key_constraints? 32 supports_deferrable_constraints? 33 end
Whether the database supports DROP TABLE IF EXISTS syntax, false by default.
# File lib/sequel/database/features.rb 37 def supports_drop_table_if_exists? 38 supports_create_table_if_not_exists? 39 end
Whether the database supports Database#foreign_key_list for parsing foreign keys.
# File lib/sequel/database/features.rb 43 def supports_foreign_key_parsing? 44 respond_to?(:foreign_key_list) 45 end
Whether the database supports Database#indexes for parsing indexes.
# File lib/sequel/database/features.rb 48 def supports_index_parsing? 49 respond_to?(:indexes) 50 end
Whether the database supports partial indexes (indexes on a subset of a table), false by default.
# File lib/sequel/database/features.rb 54 def supports_partial_indexes? 55 false 56 end
Whether the database and adapter support prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/features.rb 60 def supports_prepared_transactions? 61 false 62 end
Whether the database and adapter support savepoints, false by default.
# File lib/sequel/database/features.rb 65 def supports_savepoints? 66 false 67 end
Whether the database and adapter support savepoints inside prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/features.rb 71 def supports_savepoints_in_prepared_transactions? 72 supports_prepared_transactions? && supports_savepoints? 73 end
Whether the database supports schema parsing via Database#schema
.
# File lib/sequel/database/features.rb 76 def supports_schema_parsing? 77 respond_to?(:schema_parse_table, true) 78 end
Whether the database supports Database#tables for getting list of tables.
# File lib/sequel/database/features.rb 81 def supports_table_listing? 82 respond_to?(:tables) 83 end
Whether the database and adapter support transaction isolation levels, false by default.
# File lib/sequel/database/features.rb 91 def supports_transaction_isolation_levels? 92 false 93 end
Whether DDL statements work correctly in transactions, false by default.
# File lib/sequel/database/features.rb 96 def supports_transactional_ddl? 97 false 98 end
Whether the database supports Database#views for getting list of views.
# File lib/sequel/database/features.rb 86 def supports_view_listing? 87 respond_to?(:views) 88 end
Whether CREATE VIEW … WITH CHECK OPTION is supported, false by default.
# File lib/sequel/database/features.rb 101 def supports_views_with_check_option? 102 !!view_with_check_option_support 103 end
Whether CREATE VIEW … WITH LOCAL CHECK OPTION is supported, false by default.
# File lib/sequel/database/features.rb 106 def supports_views_with_local_check_option? 107 view_with_check_option_support == :local 108 end
Private Instance Methods
Whether the database supports adding primary key constraints on NULLable columns, automatically making them NOT NULL. If false, the columns must be set NOT NULL before the primary key constraint is added.
# File lib/sequel/database/features.rb 115 def can_add_primary_key_constraint_on_nullable_columns? 116 true 117 end
Whether this dataset considers unquoted identifiers as uppercase. True by default as that is the SQL standard
# File lib/sequel/database/features.rb 121 def folds_unquoted_identifiers_to_uppercase? 122 true 123 end
Whether the database supports combining multiple alter table operations into a single query, false by default.
# File lib/sequel/database/features.rb 127 def supports_combining_alter_table_ops? 128 false 129 end
Whether the database supports CREATE OR REPLACE VIEW. If not, support will be emulated by dropping the view first. false by default.
# File lib/sequel/database/features.rb 133 def supports_create_or_replace_view? 134 false 135 end
Whether the database supports named column constraints. True by default. Those that don't support named column constraints have to have column constraints converted to table constraints if the column constraints have names.
# File lib/sequel/database/features.rb 141 def supports_named_column_constraints? 142 true 143 end
Don't advertise support for WITH CHECK OPTION by default.
# File lib/sequel/database/features.rb 146 def view_with_check_option_support 147 nil 148 end