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:

  • :host- Defaults to “localhost”.

  • :port- Defaults to 5432.

  • :username- Defaults to nothing.

  • :password- Defaults to nothing.

  • :database- The name of the database. No default, must be provided.

  • :schema_search_path- An optional schema search path for the connection given as a string of comma-separated schema names. This is backward-compatible with the :schema_orderoption.

  • :encoding- An optional client encoding that is used in a SET client_encoding TO <encoding>call on the connection.

  • :min_messages- An optional client min messages that is used in a SET client_min_messages TO <min_messages>call on the connection.

Namespace
Methods
A
B
C
D
E
I
N
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P
Q
R
S
T
U
Constants
ADAPTER_NAME = 'PostgreSQL'
 
NATIVE_DATABASE_TYPES = { :primary_key => "serial primary key", :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" }, :tsvector => { :name => "tsvector" } }
 
FOREIGN_KEY_VIOLATION = "23503"
 

See www.postgresql.org/docs/9.1/static/errcodes-appendix.html

UNIQUE_VIOLATION = "23505"
 
FEATURE_NOT_SUPPORTED = "0A000"
 
MONEY_COLUMN_TYPE_OID = 790
 

The internal PostgreSQL identifier of the money data type.

BYTEA_COLUMN_TYPE_OID = 17
 

The internal PostgreSQL identifier of the BYTEA data type.

Class Public methods
new(connection, logger, connection_parameters, config)

Initializes and connects a PostgreSQL adapter.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 309
def initialize(connection, logger, connection_parameters, config)
  super(connection, logger)

  if config.fetch(:prepared_statements) { true }
    @visitor = Arel::Visitors::PostgreSQL.new self
  else
    @visitor = BindSubstitution.new self
  end

  @connection_parameters, @config = connection_parameters, config

  # @local_tz is initialized as nil to avoid warnings when connect tries to use it
  @local_tz = nil
  @table_alias_length = nil

  connect
  @statements = StatementPool.new @connection,
                                  config.fetch(:statement_limit) { 1000 }

  if postgresql_version < 80200
    raise "Your version of PostgreSQL (#{postgresql_version}) is too old, please upgrade!"
  end

  @local_tz = execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
end
Instance Public methods
active?()

Is this connection alive and ready for queries?

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 341
def active?
  @connection.query 'SELECT 1'
  true
rescue PGError
  false
end
adapter_name()

Returns 'PostgreSQL' as adapter name for identification purposes.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 238
def adapter_name
  ADAPTER_NAME
end
add_column(table_name, column_name, type, options = {})

Adds a new column to the named table. See ActiveRecord::ConnectionAdapters::TableDefinition#column for details of the options you can use.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1017
def add_column(table_name, column_name, type, options = {})
  clear_cache!
  add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD COLUMN #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
  add_column_options!(add_column_sql, options)

  execute add_column_sql
end
begin_db_transaction()

Begins a transaction.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 698
def begin_db_transaction
  execute "BEGIN"
end
change_column(table_name, column_name, type, options = {})

Changes the column of a table.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1026
def change_column(table_name, column_name, type, options = {})
  clear_cache!
  quoted_table_name = quote_table_name(table_name)

  execute "ALTER TABLE #{quoted_table_name} ALTER COLUMN #{quote_column_name(column_name)} TYPE #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"

  change_column_default(table_name, column_name, options[:default]) if options_include_default?(options)
  change_column_null(table_name, column_name, options[:null], options[:default]) if options.key?(:null)
end
change_column_default(table_name, column_name, default)

Changes the default value of a table column.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1037
def change_column_default(table_name, column_name, default)
  clear_cache!
  execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT #{quote(default)}"
end
change_column_null(table_name, column_name, null, default = nil)
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1042
def change_column_null(table_name, column_name, null, default = nil)
  clear_cache!
  unless null || default.nil?
    execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
  end
  execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL")
end
clear_cache!()

Clears the prepared statements cache.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 336
def clear_cache!
  @statements.clear
end
client_min_messages()

Returns the current client message level.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 896
def client_min_messages
  query('SHOW client_min_messages', 'SCHEMA')[0][0]
end
client_min_messages=(level)

Set the client message level.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 901
def client_min_messages=(level)
  execute("SET client_min_messages TO '#{level}'", 'SCHEMA')
end
columns(table_name, name = nil)

Returns the list of all column definitions for a table.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 853
def columns(table_name, name = nil)
  # Limit, precision, and scale are all handled by the superclass.
  column_definitions(table_name).collect do |column_name, type, default, notnull|
    PostgreSQLColumn.new(column_name, default, type, notnull == 'f')
  end
end
commit_db_transaction()

Commits a transaction.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 703
def commit_db_transaction
  execute "COMMIT"
end
create_database(name, options = {})

Create a new PostgreSQL database. Options include :owner, :template, :encoding, :tablespace, and :connection_limit(note that MySQL uses :charsetwhile PostgreSQL uses :encoding).

Example:

create_database config[:database], config
create_database 'foo_development', :encoding => 'unicode'
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 744
def create_database(name, options = {})
  options = options.reverse_merge(:encoding => "utf8")

  option_string = options.symbolize_keys.sum do |key, value|
    case key
    when :owner
      " OWNER = \"#{value}\""
    when :template
      " TEMPLATE = \"#{value}\""
    when :encoding
      " ENCODING = '#{value}'"
    when :tablespace
      " TABLESPACE = \"#{value}\""
    when :connection_limit
      " CONNECTION LIMIT = #{value}"
    else
      ""
    end
  end

  execute "CREATE DATABASE #{quote_table_name(name)}#{option_string}"
end
create_savepoint()
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 716
def create_savepoint
  execute("SAVEPOINT #{current_savepoint_name}")
end
current_database()

Returns the current database name.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 861
def current_database
  query('select current_database()', 'SCHEMA')[0][0]
end
current_schema()

Returns the current schema name.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 866
def current_schema
  query('SELECT current_schema', 'SCHEMA')[0][0]
end
disconnect!()

Disconnects from the database if already connected. Otherwise, this method does nothing.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 363
def disconnect!
  clear_cache!
  @connection.close rescue nil
end
encoding()

Returns the current database encoding format.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 871
      def encoding
        query("          SELECT pg_encoding_to_char(pg_database.encoding) FROM pg_database
          WHERE pg_database.datname LIKE '#{current_database}'
", 'SCHEMA')[0][0]
      end
escape_bytea(value)

Escapes binary strings for bytea input to the database.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 416
def escape_bytea(value)
  @connection.escape_bytea(value) if value
end
exec_delete(sql, name = 'SQL', binds = [])
Also aliased as: exec_update
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 669
def exec_delete(sql, name = 'SQL', binds = [])
  log(sql, name, binds) do
    result = binds.empty? ? exec_no_cache(sql, binds) :
                            exec_cache(sql, binds)
    affected = result.cmd_tuples
    result.clear
    affected
  end
end
exec_query(sql, name = 'SQL', binds = [])
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 658
def exec_query(sql, name = 'SQL', binds = [])
  log(sql, name, binds) do
    result = binds.empty? ? exec_no_cache(sql, binds) :
                            exec_cache(sql, binds)

    ret = ActiveRecord::Result.new(result.fields, result_as_array(result))
    result.clear
    return ret
  end
end
exec_update(sql, name = 'SQL', binds = [])
Alias for: exec_delete
execute(sql, name = nil)

Executes an SQL statement, returning a PGresult object on success or raising a PGError exception otherwise.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 648
def execute(sql, name = nil)
  log(sql, name) do
    @connection.async_exec(sql)
  end
end
explain(arel, binds = [])

DATABASE STATEMENTS ======================================

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 532
def explain(arel, binds = [])
  sql = "EXPLAIN #{to_sql(arel, binds)}"
  ExplainPrettyPrinter.new.pp(exec_query(sql, 'EXPLAIN', binds))
end
index_name_length()
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1064
def index_name_length
  63
end
indexes(table_name, name = nil)

Returns an array of indexes for the given table.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 814
      def indexes(table_name, name = nil)
         result = query("           SELECT distinct i.relname, d.indisunique, d.indkey, pg_get_indexdef(d.indexrelid), t.oid
           FROM pg_class t
           INNER JOIN pg_index d ON t.oid = d.indrelid
           INNER JOIN pg_class i ON d.indexrelid = i.oid
           WHERE i.relkind = 'i'
             AND d.indisprimary = 'f'
             AND t.relname = '#{table_name}'
             AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = ANY (current_schemas(false)) )
          ORDER BY i.relname
", 'SCHEMA')


        result.map do |row|
          index_name = row[0]
          unique = row[1] == 't'
          indkey = row[2].split(" ")
          inddef = row[3]
          oid = row[4]

          columns = Hash[query("          SELECT a.attnum, a.attname
          FROM pg_attribute a
          WHERE a.attrelid = #{oid}
          AND a.attnum IN (#{indkey.join(",")})
", "SCHEMA")]

          column_names = columns.values_at(*indkey).compact

          # add info on sort order for columns (only desc order is explicitly specified, asc is the default)
          desc_order_columns = inddef.scan(/(\w+) DESC/).flatten
          orders = desc_order_columns.any? ? Hash[desc_order_columns.map {|order_column| [order_column, :desc]}] : {}

          column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders)
        end.compact
      end
insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

Executes an INSERT query and returns the new record's ID

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 581
def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
  unless pk
    # Extract the table from the insert sql. Yuck.
    table_ref = extract_table_ref_from_insert_sql(sql)
    pk = primary_key(table_ref) if table_ref
  end

  if pk
    select_value("#{sql} RETURNING #{quote_column_name(pk)}")
  else
    super
  end
end
outside_transaction?()
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 712
def outside_transaction?
  @connection.transaction_status == PGconn::PQTRANS_IDLE
end
primary_key(table)

Returns just a table's primary key

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 987
      def primary_key(table)
        row = exec_query("          SELECT attr.attname
          FROM pg_attribute attr
          INNER JOIN pg_constraint cons ON attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1]
          WHERE cons.contype = 'p'
            AND cons.conrelid = '#{quote_table_name(table)}'::regclass
", 'SCHEMA').rows.first

        row && row.first
      end
quote_table_name(name)

Checks the following cases:

  • table_name

  • “table.name”

  • schema_name.table_name

  • schema_name.“table.name”

  • “schema.name”.table_name

  • “schema.name”.“table.name”

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 481
def quote_table_name(name)
  schema, name_part = extract_pg_identifier_from_name(name.to_s)

  unless name_part
    quote_column_name(schema)
  else
    table_name, name_part = extract_pg_identifier_from_name(name_part)
    "#{quote_column_name(schema)}.#{quote_column_name(table_name)}"
  end
end
reconnect!()

Close then reopen the connection.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 349
def reconnect!
  clear_cache!
  @connection.reset
  @open_transactions = 0
  configure_connection
end
release_savepoint()
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 724
def release_savepoint
  execute("RELEASE SAVEPOINT #{current_savepoint_name}")
end
rename_column(table_name, column_name, new_column_name)

Renames a column in a table.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1051
def rename_column(table_name, column_name, new_column_name)
  clear_cache!
  execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}"
end
rename_index(table_name, old_name, new_name)
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1060
def rename_index(table_name, old_name, new_name)
  execute "ALTER INDEX #{quote_column_name(old_name)} RENAME TO #{quote_table_name(new_name)}"
end
rename_table(name, new_name)

Renames a table. Also renames a table's primary key sequence if the sequence name matches the Active Record default.

Example:

rename_table('octopuses', 'octopi')
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1005
def rename_table(name, new_name)
  clear_cache!
  execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
  pk, seq = pk_and_sequence_for(new_name)
  if seq == "#{name}_#{pk}_seq"
    new_seq = "#{new_name}_#{pk}_seq"
    execute "ALTER TABLE #{quote_table_name(seq)} RENAME TO #{quote_table_name(new_seq)}"
  end
end
reset!()
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 356
def reset!
  clear_cache!
  super
end
rollback_db_transaction()

Aborts a transaction.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 708
def rollback_db_transaction
  execute "ROLLBACK"
end
rollback_to_savepoint()
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 720
def rollback_to_savepoint
  execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
end
schema_exists?(name)

Returns true if schema exists.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 805
      def schema_exists?(name)
        exec_query("          SELECT COUNT(*)
          FROM pg_namespace
          WHERE nspname = '#{name}'
", 'SCHEMA').rows.first[0].to_i > 0
      end
schema_search_path()

Returns the active schema search path.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 891
def schema_search_path
  @schema_search_path ||= query('SHOW search_path', 'SCHEMA')[0][0]
end
schema_search_path=(schema_csv)

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 activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 883
def schema_search_path=(schema_csv)
  if schema_csv
    execute("SET search_path TO #{schema_csv}", 'SCHEMA')
    @schema_search_path = schema_csv
  end
end
select_rows(sql, name = nil)

Executes a SELECT query and returns an array of rows. Each row is an array of field values.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 576
def select_rows(sql, name = nil)
  select_raw(sql, name).last
end
serial_sequence(table, column)
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 912
      def serial_sequence(table, column)
        result = exec_query("          SELECT pg_get_serial_sequence('#{table}', '#{column}')
", 'SCHEMA')
        result.rows.first.first
      end
session_auth=(user)

Set the authorized user for this session

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 508
def session_auth=(user)
  clear_cache!
  exec_query "SET SESSION AUTHORIZATION #{user}"
end
set_standard_conforming_strings()

Enable standard-conforming strings if available.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 383
def set_standard_conforming_strings
  old, self.client_min_messages = client_min_messages, 'panic'
  execute('SET standard_conforming_strings = on', 'SCHEMA') rescue nil
ensure
  self.client_min_messages = old
end
sql_for_insert(sql, pk, id_value, sequence_name, binds)
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 680
def sql_for_insert(sql, pk, id_value, sequence_name, binds)
  unless pk
    # Extract the table from the insert sql. Yuck.
    table_ref = extract_table_ref_from_insert_sql(sql)
    pk = primary_key(table_ref) if table_ref
  end

  sql = "#{sql} RETURNING #{quote_column_name(pk)}" if pk

  [sql, binds]
end
substitute_at(column, index)
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 654
def substitute_at(column, index)
  Arel::Nodes::BindParam.new "$#{index + 1}"
end
supports_ddl_transactions?()
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 394
def supports_ddl_transactions?
  true
end
supports_explain?()

Returns true.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 404
def supports_explain?
  true
end
supports_index_sort_order?()
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 248
def supports_index_sort_order?
  true
end
supports_insert_with_returning?()
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 390
def supports_insert_with_returning?
  true
end
supports_migrations?()

Returns true, since this connection adapter supports migrations.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 373
def supports_migrations?
  true
end
supports_savepoints?()

Returns true, since this connection adapter supports savepoints.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 399
def supports_savepoints?
  true
end
supports_statement_cache?()

Returns true, since this connection adapter supports prepared statement caching.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 244
def supports_statement_cache?
  true
end
table_alias_length()

Returns the configured supported identifier length supported by PostgreSQL

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 409
def table_alias_length
  @table_alias_length ||= query('SHOW max_identifier_length')[0][0].to_i
end
table_exists?(name)

Returns true if table exists. If the schema is not specified as part of namethen it will only find tables within the current schema search path (regardless of permissions to access tables in other schemas)

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 787
      def table_exists?(name)
        schema, table = Utils.extract_schema_and_table(name.to_s)
        return false unless table

        binds = [[nil, table]]
        binds << [nil, schema] if schema

        exec_query("            SELECT COUNT(*)
            FROM pg_class c
            LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
            WHERE c.relkind in ('v','r')
            AND c.relname = '#{table.gsub(/(^"|"$)/,'')}'
            AND n.nspname = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'}
", 'SCHEMA').rows.first[0].to_i > 0
      end
tables(name = nil)

Returns the list of all tables in the schema search path or a specified schema.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 776
      def tables(name = nil)
        query("          SELECT tablename
          FROM pg_tables
          WHERE schemaname = ANY (current_schemas(false))
", 'SCHEMA').map { |row| row[0] }
      end
type_cast(value, column)
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 456
def type_cast(value, column)
  return super unless column

  case value
  when String
    return super unless 'bytea' == column.sql_type
    { :value => value, :format => 1 }
  else
    super
  end
end
type_to_sql(type, limit = nil, precision = nil, scale = nil)

Maps logical Rails types to PostgreSQL-specific data types.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1069
def type_to_sql(type, limit = nil, precision = nil, scale = nil)
  case type.to_s
  when 'binary'
    # PostgreSQL doesn't support limits on binary (bytea) columns.
    # The hard limit is 1Gb, because of a 32-bit size field, and TOAST.
    case limit
    when nil, 0..0x3fffffff; super(type)
    else raise(ActiveRecordError, "No binary type has byte size #{limit}.")
    end
  when 'text'
    # PostgreSQL doesn't support limits on text columns.
    # The hard limit is 1Gb, according to section 8.3 in the manual.
    case limit
    when nil, 0..0x3fffffff; super(type)
    else raise(ActiveRecordError, "The limit on text can be at most 1GB - 1byte.")
    end
  when 'integer'
    return 'integer' unless limit

    case limit
      when 1, 2; 'smallint'
      when 3, 4; 'integer'
      when 5..8; 'bigint'
      else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.")
    end
  else
    super
  end
end
unescape_bytea(value)

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 activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 423
def unescape_bytea(value)
  @connection.unescape_bytea(value) if value
end
update_sql(sql, name = nil)

Executes an UPDATE query and returns the number of affected tuples.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 693
def update_sql(sql, name = nil)
  super.cmd_tuples
end
Instance Protected methods
postgresql_version()

Returns the version of the connected PostgreSQL server.

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1138
def postgresql_version
  @connection.server_version
end
translate_exception(exception, message)
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1146
def translate_exception(exception, message)
  return exception unless exception.respond_to?(:result)

  case exception.result.try(:error_field, PGresult::PG_DIAG_SQLSTATE)
  when UNIQUE_VIOLATION
    RecordNotUnique.new(message, exception)
  when FOREIGN_KEY_VIOLATION
    InvalidForeignKey.new(message, exception)
  else
    super
  end
end