| Class | ActiveRecord::ConnectionAdapters::PostgreSQLAdapter |
| In: |
vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
|
| Parent: | AbstractAdapter |
The PostgreSQL adapter works both with the native C (ruby.scripting.ca/postgres/) and the pure Ruby (available both as gem and from rubyforge.org/frs/?group_id=234&release_id=1944) drivers.
Options:
| ADAPTER_NAME | = | 'PostgreSQL'.freeze | ||
| NATIVE_DATABASE_TYPES | = | { :primary_key => "serial primary key".freeze, :string => { :name => "character varying", :limit => 255 }, :text => { :name => "text" }, :integer => { :name => "integer" }, :float => { :name => "float" }, :decimal => { :name => "decimal" }, :datetime => { :name => "timestamp" }, :timestamp => { :name => "timestamp" }, :time => { :name => "time" }, :date => { :name => "date" }, :binary => { :name => "bytea" }, :boolean => { :name => "boolean" } | ||
| PQTRANS_IDLE | = | defined?(PGconn::PQTRANS_IDLE) ? PGconn::PQTRANS_IDLE : 0 | ruby-pg defines Ruby constants for transaction status, ruby-postgres does not. |
Initializes and connects a PostgreSQL adapter.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 206
206: def initialize(connection, logger, connection_parameters, config)
207: super(connection, logger)
208: @connection_parameters, @config = connection_parameters, config
209:
210: connect
211: end
Is this connection alive and ready for queries?
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 214
214: def active?
215: if @connection.respond_to?(:status)
216: @connection.status == PGconn::CONNECTION_OK
217: else
218: # We're asking the driver, not ActiveRecord, so use @connection.query instead of #query
219: @connection.query 'SELECT 1'
220: true
221: end
222: # postgres-pr raises a NoMethodError when querying if no connection is available.
223: rescue PGError, NoMethodError
224: false
225: end
Returns ‘PostgreSQL’ as adapter name for identification purposes.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 201
201: def adapter_name
202: ADAPTER_NAME
203: end
Adds a new column to the named table. See TableDefinition#column for details of the options you can use.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 807
807: def add_column(table_name, column_name, type, options = {})
808: default = options[:default]
809: notnull = options[:null] == false
810:
811: # Add the column.
812: execute("ALTER TABLE #{quote_table_name(table_name)} ADD COLUMN #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}")
813:
814: change_column_default(table_name, column_name, default) if options_include_default?(options)
815: change_column_null(table_name, column_name, false, default) if notnull
816: end
Begins a transaction.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 518
518: def begin_db_transaction
519: execute "BEGIN"
520: end
Changes the column of a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 819
819: def change_column(table_name, column_name, type, options = {})
820: quoted_table_name = quote_table_name(table_name)
821:
822: begin
823: execute "ALTER TABLE #{quoted_table_name} ALTER COLUMN #{quote_column_name(column_name)} TYPE #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
824: rescue ActiveRecord::StatementInvalid => e
825: raise e if postgresql_version > 80000
826: # This is PostgreSQL 7.x, so we have to use a more arcane way of doing it.
827: begin
828: begin_db_transaction
829: tmp_column_name = "#{column_name}_ar_tmp"
830: add_column(table_name, tmp_column_name, type, options)
831: execute "UPDATE #{quoted_table_name} SET #{quote_column_name(tmp_column_name)} = CAST(#{quote_column_name(column_name)} AS #{type_to_sql(type, options[:limit], options[:precision], options[:scale])})"
832: remove_column(table_name, column_name)
833: rename_column(table_name, tmp_column_name, column_name)
834: commit_db_transaction
835: rescue
836: rollback_db_transaction
837: end
838: end
839:
840: change_column_default(table_name, column_name, options[:default]) if options_include_default?(options)
841: change_column_null(table_name, column_name, options[:null], options[:default]) if options.key?(:null)
842: end
Changes the default value of a table column.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 845
845: def change_column_default(table_name, column_name, default)
846: execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT #{quote(default)}"
847: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 849
849: def change_column_null(table_name, column_name, null, default = nil)
850: unless null || default.nil?
851: execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
852: end
853: execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL")
854: end
Returns the current client message level.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 713
713: def client_min_messages
714: query('SHOW client_min_messages')[0][0]
715: end
Set the client message level.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 718
718: def client_min_messages=(level)
719: execute("SET client_min_messages TO '#{level}'")
720: end
Returns the list of all column definitions for a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 674
674: def columns(table_name, name = nil)
675: # Limit, precision, and scale are all handled by the superclass.
676: column_definitions(table_name).collect do |name, type, default, notnull|
677: PostgreSQLColumn.new(name, default, type, notnull == 'f')
678: end
679: end
Commits a transaction.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 523
523: def commit_db_transaction
524: execute "COMMIT"
525: end
Create a new PostgreSQL database. Options include :owner, :template, :encoding, :tablespace, and :connection_limit (note that MySQL uses :charset while PostgreSQL uses :encoding).
Example:
create_database config[:database], config create_database 'foo_development', :encoding => 'unicode'
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 585
585: def create_database(name, options = {})
586: options = options.reverse_merge(:encoding => "utf8")
587:
588: option_string = options.symbolize_keys.sum do |key, value|
589: case key
590: when :owner
591: " OWNER = \"#{value}\""
592: when :template
593: " TEMPLATE = \"#{value}\""
594: when :encoding
595: " ENCODING = '#{value}'"
596: when :tablespace
597: " TABLESPACE = \"#{value}\""
598: when :connection_limit
599: " CONNECTION LIMIT = #{value}"
600: else
601: ""
602: end
603: end
604:
605: execute "CREATE DATABASE #{quote_table_name(name)}#{option_string}"
606: end
Returns the current database name.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 682
682: def current_database
683: query('select current_database()')[0][0]
684: end
Close the connection.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 239
239: def disconnect!
240: @connection.close rescue nil
241: end
Returns the current database encoding format.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 687
687: def encoding
688: query("SELECT pg_encoding_to_char(pg_database.encoding) FROM pg_database\nWHERE pg_database.datname LIKE '\#{current_database}'\n")[0][0]
689: end
Escapes binary strings for bytea input to the database.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 285
285: def escape_bytea(value)
286: if PGconn.respond_to?(:escape_bytea)
287: self.class.instance_eval do
288: define_method(:escape_bytea) do |value|
289: PGconn.escape_bytea(value) if value
290: end
291: end
292: else
293: self.class.instance_eval do
294: define_method(:escape_bytea) do |value|
295: if value
296: result = ''
297: value.each_byte { |c| result << sprintf('\\\\%03o', c) }
298: result
299: end
300: end
301: end
302: end
303: escape_bytea(value)
304: end
Executes an SQL statement, returning a PGresult object on success or raising a PGError exception otherwise.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 502
502: def execute(sql, name = nil)
503: log(sql, name) do
504: if @async
505: @connection.async_exec(sql)
506: else
507: @connection.exec(sql)
508: end
509: end
510: end
Returns the list of all indexes for a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 637
637: def indexes(table_name, name = nil)
638: schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',')
639: result = query("SELECT distinct i.relname, d.indisunique, a.attname\nFROM pg_class t, pg_class i, pg_index d, pg_attribute a\nWHERE i.relkind = 'i'\nAND d.indexrelid = i.oid\nAND d.indisprimary = 'f'\nAND t.oid = d.indrelid\nAND t.relname = '\#{table_name}'\nAND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname IN (\#{schemas}) )\nAND a.attrelid = t.oid\nAND ( d.indkey[0]=a.attnum OR d.indkey[1]=a.attnum\nOR d.indkey[2]=a.attnum OR d.indkey[3]=a.attnum\nOR d.indkey[4]=a.attnum OR d.indkey[5]=a.attnum\nOR d.indkey[6]=a.attnum OR d.indkey[7]=a.attnum\nOR d.indkey[8]=a.attnum OR d.indkey[9]=a.attnum )\nORDER BY i.relname\n", name)
640:
641: current_index = nil
642: indexes = []
643:
644: result.each do |row|
645: if current_index != row[0]
646: indexes << IndexDefinition.new(table_name, row[0], row[1] == "t", [])
647: current_index = row[0]
648: end
649:
650: indexes.last.columns << row[2]
651: end
652:
653: indexes
654: end
Executes an INSERT query and returns the new record‘s ID
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 435
435: def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
436: # Extract the table from the insert sql. Yuck.
437: table = sql.split(" ", 4)[2].gsub('"', '')
438:
439: # Try an insert with 'returning id' if available (PG >= 8.2)
440: if supports_insert_with_returning?
441: pk, sequence_name = *pk_and_sequence_for(table) unless pk
442: if pk
443: id = select_value("#{sql} RETURNING #{quote_column_name(pk)}")
444: clear_query_cache
445: return id
446: end
447: end
448:
449: # Otherwise, insert then grab last_insert_id.
450: if insert_id = super
451: insert_id
452: else
453: # If neither pk nor sequence name is given, look them up.
454: unless pk || sequence_name
455: pk, sequence_name = *pk_and_sequence_for(table)
456: end
457:
458: # If a pk is given, fallback to default sequence name.
459: # Don't fetch last insert id for a table without a pk.
460: if pk && sequence_name ||= default_sequence_name(table, pk)
461: last_insert_id(table, sequence_name)
462: end
463: end
464: end
Close then reopen the connection.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 228
228: def reconnect!
229: if @connection.respond_to?(:reset)
230: @connection.reset
231: configure_connection
232: else
233: disconnect!
234: connect
235: end
236: end
Drops an index from a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 862
862: def remove_index(table_name, options = {})
863: execute "DROP INDEX #{index_name(table_name, options)}"
864: end
Renames a column in a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 857
857: def rename_column(table_name, column_name, new_column_name)
858: execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}"
859: end
Renames a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 801
801: def rename_table(name, new_name)
802: execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
803: end
Aborts a transaction.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 528
528: def rollback_db_transaction
529: execute "ROLLBACK"
530: end
Returns the active schema search path.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 708
708: def schema_search_path
709: @schema_search_path ||= query('SHOW search_path')[0][0]
710: end
Sets the schema search path to a string of comma-separated schema names. Names beginning with $ have to be quoted (e.g. $user => ’$user’). See: www.postgresql.org/docs/current/static/ddl-schemas.html
This should be not be called manually but set in database.yml.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 700
700: def schema_search_path=(schema_csv)
701: if schema_csv
702: execute "SET search_path TO #{schema_csv}"
703: @schema_search_path = schema_csv
704: end
705: end
Executes a SELECT query and returns an array of rows. Each row is an array of field values.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 430
430: def select_rows(sql, name = nil)
431: select_raw(sql, name).last
432: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 272
272: def supports_ddl_transactions?
273: true
274: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 268
268: def supports_insert_with_returning?
269: postgresql_version >= 80200
270: end
Does PostgreSQL support migrations?
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 248
248: def supports_migrations?
249: true
250: end
Does PostgreSQL support standard conforming strings?
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 253
253: def supports_standard_conforming_strings?
254: # Temporarily set the client message level above error to prevent unintentional
255: # error messages in the logs when working on a PostgreSQL database server that
256: # does not support standard conforming strings.
257: client_min_messages_old = client_min_messages
258: self.client_min_messages = 'panic'
259:
260: # postgres-pr does not raise an exception when client_min_messages is set higher
261: # than error and "SHOW standard_conforming_strings" fails, but returns an empty
262: # PGresult instead.
263: has_support = query('SHOW standard_conforming_strings')[0][0] rescue false
264: self.client_min_messages = client_min_messages_old
265: has_support
266: end
Returns the configured supported identifier length supported by PostgreSQL, or report the default of 63 on PostgreSQL 7.x.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 278
278: def table_alias_length
279: @table_alias_length ||= (postgresql_version >= 80000 ? query('SHOW max_identifier_length')[0][0].to_i : 63)
280: end
Returns the list of all tables in the schema search path or a specified schema.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 626
626: def tables(name = nil)
627: schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',')
628: query("SELECT tablename\nFROM pg_tables\nWHERE schemaname IN (\#{schemas})\n", name).map { |row| row[0] }
629: end
Wrap a block in a transaction. Returns result of block.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 542
542: def transaction(start_db_transaction = true)
543: transaction_open = false
544: begin
545: if block_given?
546: if start_db_transaction
547: begin_db_transaction
548: transaction_open = true
549: end
550: yield
551: end
552: rescue Exception => database_transaction_rollback
553: if transaction_open && transaction_active?
554: transaction_open = false
555: rollback_db_transaction
556: end
557: raise unless database_transaction_rollback.is_a? ActiveRecord::Rollback
558: end
559: ensure
560: if transaction_open && transaction_active?
561: begin
562: commit_db_transaction
563: rescue Exception => database_transaction_rollback
564: rollback_db_transaction
565: raise
566: end
567: end
568: end
Check whether a transaction is active.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 537
537: def transaction_active?
538: @connection.transaction_status != PQTRANS_IDLE
539: end
Maps logical Rails types to PostgreSQL-specific data types.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 867
867: def type_to_sql(type, limit = nil, precision = nil, scale = nil)
868: return super unless type.to_s == 'integer'
869:
870: case limit
871: when 1..2; 'smallint'
872: when 3..4, nil; 'integer'
873: when 5..8; 'bigint'
874: else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.")
875: end
876: end
Unescapes bytea output from a database to the binary string it represents. NOTE: This is NOT an inverse of escape_bytea! This is only to be used
on escaped binary output from database drive.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 309
309: def unescape_bytea(value)
310: # In each case, check if the value actually is escaped PostgreSQL bytea output
311: # or an unescaped Active Record attribute that was just written.
312: if PGconn.respond_to?(:unescape_bytea)
313: self.class.instance_eval do
314: define_method(:unescape_bytea) do |value|
315: if value =~ /\\\d{3}/
316: PGconn.unescape_bytea(value)
317: else
318: value
319: end
320: end
321: end
322: else
323: self.class.instance_eval do
324: define_method(:unescape_bytea) do |value|
325: if value =~ /\\\d{3}/
326: result = ''
327: i, max = 0, value.size
328: while i < max
329: char = value[i]
330: if char == ?\\
331: if value[i+1] == ?\\
332: char = ?\\
333: i += 1
334: else
335: char = value[i+1..i+3].oct
336: i += 3
337: end
338: end
339: result << char
340: i += 1
341: end
342: result
343: else
344: value
345: end
346: end
347: end
348: end
349: unescape_bytea(value)
350: end
Executes an UPDATE query and returns the number of affected tuples.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 513
513: def update_sql(sql, name = nil)
514: super.cmd_tuples
515: end
Returns the version of the connected PostgreSQL version.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 915
915: def postgresql_version
916: @postgresql_version ||=
917: if @connection.respond_to?(:server_version)
918: @connection.server_version
919: else
920: # Mimic PGconn.server_version behavior
921: begin
922: query('SELECT version()')[0][0] =~ /PostgreSQL (\d+)\.(\d+)\.(\d+)/
923: ($1.to_i * 10000) + ($2.to_i * 100) + $3.to_i
924: rescue
925: 0
926: end
927: end
928: end