| 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" }, :xml => { :name => "xml" } |
Initializes and connects a PostgreSQL adapter.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 213
213: def initialize(connection, logger, connection_parameters, config)
214: super(connection, logger)
215: @connection_parameters, @config = connection_parameters, config
216:
217: connect
218: end
Is this connection alive and ready for queries?
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 221
221: def active?
222: if @connection.respond_to?(:status)
223: @connection.status == PGconn::CONNECTION_OK
224: else
225: # We're asking the driver, not ActiveRecord, so use @connection.query instead of #query
226: @connection.query 'SELECT 1'
227: true
228: end
229: # postgres-pr raises a NoMethodError when querying if no connection is available.
230: rescue PGError, NoMethodError
231: false
232: end
Returns ‘PostgreSQL’ as adapter name for identification purposes.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 208
208: def adapter_name
209: ADAPTER_NAME
210: 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 845
845: def add_column(table_name, column_name, type, options = {})
846: default = options[:default]
847: notnull = options[:null] == false
848:
849: # Add the column.
850: 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])}")
851:
852: change_column_default(table_name, column_name, default) if options_include_default?(options)
853: change_column_null(table_name, column_name, false, default) if notnull
854: end
Begins a transaction.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 565
565: def begin_db_transaction
566: execute "BEGIN"
567: end
Changes the column of a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 857
857: def change_column(table_name, column_name, type, options = {})
858: quoted_table_name = quote_table_name(table_name)
859:
860: begin
861: execute "ALTER TABLE #{quoted_table_name} ALTER COLUMN #{quote_column_name(column_name)} TYPE #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
862: rescue ActiveRecord::StatementInvalid => e
863: raise e if postgresql_version > 80000
864: # This is PostgreSQL 7.x, so we have to use a more arcane way of doing it.
865: begin
866: begin_db_transaction
867: tmp_column_name = "#{column_name}_ar_tmp"
868: add_column(table_name, tmp_column_name, type, options)
869: 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])})"
870: remove_column(table_name, column_name)
871: rename_column(table_name, tmp_column_name, column_name)
872: commit_db_transaction
873: rescue
874: rollback_db_transaction
875: end
876: end
877:
878: change_column_default(table_name, column_name, options[:default]) if options_include_default?(options)
879: change_column_null(table_name, column_name, options[:null], options[:default]) if options.key?(:null)
880: end
Changes the default value of a table column.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 883
883: def change_column_default(table_name, column_name, default)
884: execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT #{quote(default)}"
885: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 887
887: def change_column_null(table_name, column_name, null, default = nil)
888: unless null || default.nil?
889: execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
890: end
891: execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL")
892: end
Returns the current client message level.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 745
745: def client_min_messages
746: query('SHOW client_min_messages')[0][0]
747: end
Set the client message level.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 750
750: def client_min_messages=(level)
751: execute("SET client_min_messages TO '#{level}'")
752: end
Returns the list of all column definitions for a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 706
706: def columns(table_name, name = nil)
707: # Limit, precision, and scale are all handled by the superclass.
708: column_definitions(table_name).collect do |name, type, default, notnull|
709: PostgreSQLColumn.new(name, default, type, notnull == 'f')
710: end
711: end
Commits a transaction.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 570
570: def commit_db_transaction
571: execute "COMMIT"
572: 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 613
613: def create_database(name, options = {})
614: options = options.reverse_merge(:encoding => "utf8")
615:
616: option_string = options.symbolize_keys.sum do |key, value|
617: case key
618: when :owner
619: " OWNER = \"#{value}\""
620: when :template
621: " TEMPLATE = \"#{value}\""
622: when :encoding
623: " ENCODING = '#{value}'"
624: when :tablespace
625: " TABLESPACE = \"#{value}\""
626: when :connection_limit
627: " CONNECTION LIMIT = #{value}"
628: else
629: ""
630: end
631: end
632:
633: execute "CREATE DATABASE #{quote_table_name(name)}#{option_string}"
634: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 587
587: def create_savepoint
588: execute("SAVEPOINT #{current_savepoint_name}")
589: end
Returns the current database name.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 714
714: def current_database
715: query('select current_database()')[0][0]
716: end
Close the connection.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 246
246: def disconnect!
247: @connection.close rescue nil
248: end
Returns the current database encoding format.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 719
719: def encoding
720: query("SELECT pg_encoding_to_char(pg_database.encoding) FROM pg_database\nWHERE pg_database.datname LIKE '\#{current_database}'\n")[0][0]
721: end
Escapes binary strings for bytea input to the database.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 301
301: def escape_bytea(value)
302: if @connection.respond_to?(:escape_bytea)
303: self.class.instance_eval do
304: define_method(:escape_bytea) do |value|
305: @connection.escape_bytea(value) if value
306: end
307: end
308: elsif PGconn.respond_to?(:escape_bytea)
309: self.class.instance_eval do
310: define_method(:escape_bytea) do |value|
311: PGconn.escape_bytea(value) if value
312: end
313: end
314: else
315: self.class.instance_eval do
316: define_method(:escape_bytea) do |value|
317: if value
318: result = ''
319: value.each_byte { |c| result << sprintf('\\\\%03o', c) }
320: result
321: end
322: end
323: end
324: end
325: escape_bytea(value)
326: 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 549
549: def execute(sql, name = nil)
550: log(sql, name) do
551: if @async
552: @connection.async_exec(sql)
553: else
554: @connection.exec(sql)
555: end
556: end
557: end
Returns the list of all indexes for a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 665
665: def indexes(table_name, name = nil)
666: schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',')
667: result = query("SELECT distinct i.relname, d.indisunique, d.indkey, t.oid\nFROM pg_class t, pg_class i, pg_index d\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}) )\nORDER BY i.relname\n", name)
668:
669:
670: indexes = []
671:
672: indexes = result.map do |row|
673: index_name = row[0]
674: unique = row[1] == 't'
675: indkey = row[2].split(" ")
676: oid = row[3]
677:
678: columns = query("SELECT a.attname, a.attnum\nFROM pg_attribute a\nWHERE a.attrelid = \#{oid}\nAND a.attnum IN (\#{indkey.join(\",\")})\n", "Columns for index #{row[0]} on #{table_name}").inject({}) {|attlist, r| attlist[r[1]] = r[0]; attlist}
679:
680: column_names = indkey.map {|attnum| columns[attnum] }
681: IndexDefinition.new(table_name, index_name, unique, column_names)
682:
683: end
684:
685: indexes
686: 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 482
482: def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
483: # Extract the table from the insert sql. Yuck.
484: table = sql.split(" ", 4)[2].gsub('"', '')
485:
486: # Try an insert with 'returning id' if available (PG >= 8.2)
487: if supports_insert_with_returning?
488: pk, sequence_name = *pk_and_sequence_for(table) unless pk
489: if pk
490: id = select_value("#{sql} RETURNING #{quote_column_name(pk)}")
491: clear_query_cache
492: return id
493: end
494: end
495:
496: # Otherwise, insert then grab last_insert_id.
497: if insert_id = super
498: insert_id
499: else
500: # If neither pk nor sequence name is given, look them up.
501: unless pk || sequence_name
502: pk, sequence_name = *pk_and_sequence_for(table)
503: end
504:
505: # If a pk is given, fallback to default sequence name.
506: # Don't fetch last insert id for a table without a pk.
507: if pk && sequence_name ||= default_sequence_name(table, pk)
508: last_insert_id(table, sequence_name)
509: end
510: end
511: end
The ruby-pg driver supports inspecting the transaction status, while the ruby-postgres driver does not.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 582
582: def outside_transaction?
583: @connection.transaction_status == PGconn::PQTRANS_IDLE
584: end
Returns just a table‘s primary key
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 833
833: def primary_key(table)
834: pk_and_sequence = pk_and_sequence_for(table)
835: pk_and_sequence && pk_and_sequence.first
836: end
Checks the following cases:
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 427
427: def quote_table_name(name)
428: schema, name_part = extract_pg_identifier_from_name(name.to_s)
429:
430: unless name_part
431: quote_column_name(schema)
432: else
433: table_name, name_part = extract_pg_identifier_from_name(name_part)
434: "#{quote_column_name(schema)}.#{quote_column_name(table_name)}"
435: end
436: end
Close then reopen the connection.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 235
235: def reconnect!
236: if @connection.respond_to?(:reset)
237: @connection.reset
238: configure_connection
239: else
240: disconnect!
241: connect
242: end
243: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 595
595: def release_savepoint
596: execute("RELEASE SAVEPOINT #{current_savepoint_name}")
597: end
Drops an index from a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 900
900: def remove_index(table_name, options = {})
901: execute "DROP INDEX #{quote_table_name(index_name(table_name, options))}"
902: end
Renames a column in a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 895
895: def rename_column(table_name, column_name, new_column_name)
896: execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}"
897: end
Renames a table.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 839
839: def rename_table(name, new_name)
840: execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
841: end
Aborts a transaction.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 575
575: def rollback_db_transaction
576: execute "ROLLBACK"
577: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 591
591: def rollback_to_savepoint
592: execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
593: end
Returns the active schema search path.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 740
740: def schema_search_path
741: @schema_search_path ||= query('SHOW search_path')[0][0]
742: 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 732
732: def schema_search_path=(schema_csv)
733: if schema_csv
734: execute "SET search_path TO #{schema_csv}"
735: @schema_search_path = schema_csv
736: end
737: 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 477
477: def select_rows(sql, name = nil)
478: select_raw(sql, name).last
479: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 284
284: def supports_ddl_transactions?
285: true
286: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 280
280: def supports_insert_with_returning?
281: postgresql_version >= 80200
282: end
Does PostgreSQL support migrations?
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 255
255: def supports_migrations?
256: true
257: end
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 288
288: def supports_savepoints?
289: true
290: end
Does PostgreSQL support standard conforming strings?
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 265
265: def supports_standard_conforming_strings?
266: # Temporarily set the client message level above error to prevent unintentional
267: # error messages in the logs when working on a PostgreSQL database server that
268: # does not support standard conforming strings.
269: client_min_messages_old = client_min_messages
270: self.client_min_messages = 'panic'
271:
272: # postgres-pr does not raise an exception when client_min_messages is set higher
273: # than error and "SHOW standard_conforming_strings" fails, but returns an empty
274: # PGresult instead.
275: has_support = query('SHOW standard_conforming_strings')[0][0] rescue false
276: self.client_min_messages = client_min_messages_old
277: has_support
278: 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 294
294: def table_alias_length
295: @table_alias_length ||= (postgresql_version >= 80000 ? query('SHOW max_identifier_length')[0][0].to_i : 63)
296: 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 654
654: def tables(name = nil)
655: schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',')
656: query("SELECT tablename\nFROM pg_tables\nWHERE schemaname IN (\#{schemas})\n", name).map { |row| row[0] }
657: end
Maps logical Rails types to PostgreSQL-specific data types.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 905
905: def type_to_sql(type, limit = nil, precision = nil, scale = nil)
906: return super unless type.to_s == 'integer'
907:
908: case limit
909: when 1..2; 'smallint'
910: when 3..4, nil; 'integer'
911: when 5..8; 'bigint'
912: else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.")
913: end
914: 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 331
331: def unescape_bytea(value)
332: # In each case, check if the value actually is escaped PostgreSQL bytea output
333: # or an unescaped Active Record attribute that was just written.
334: if PGconn.respond_to?(:unescape_bytea)
335: self.class.instance_eval do
336: define_method(:unescape_bytea) do |value|
337: if value =~ /\\\d{3}/
338: PGconn.unescape_bytea(value)
339: else
340: value
341: end
342: end
343: end
344: else
345: self.class.instance_eval do
346: define_method(:unescape_bytea) do |value|
347: if value =~ /\\\d{3}/
348: result = ''
349: i, max = 0, value.size
350: while i < max
351: char = value[i]
352: if char == ?\\
353: if value[i+1] == ?\\
354: char = ?\\
355: i += 1
356: else
357: char = value[i+1..i+3].oct
358: i += 3
359: end
360: end
361: result << char
362: i += 1
363: end
364: result
365: else
366: value
367: end
368: end
369: end
370: end
371: unescape_bytea(value)
372: 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 560
560: def update_sql(sql, name = nil)
561: super.cmd_tuples
562: end
Returns the version of the connected PostgreSQL version.
# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 953
953: def postgresql_version
954: @postgresql_version ||=
955: if @connection.respond_to?(:server_version)
956: @connection.server_version
957: else
958: # Mimic PGconn.server_version behavior
959: begin
960: query('SELECT version()')[0][0] =~ /PostgreSQL (\d+)\.(\d+)\.(\d+)/
961: ($1.to_i * 10000) + ($2.to_i * 100) + $3.to_i
962: rescue
963: 0
964: end
965: end
966: end