# File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 52
52:       def initialize(connection, logger, config = {})
53:         super(connection, logger)
54:         @config = config
55:         configure_connection
56:       end

    # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 59
59:       def active?
60:         if @connection.respond_to?(:status)
61:           @connection.status == PGconn::CONNECTION_OK
62:         else
63:           @connection.query 'SELECT 1'
64:           true
65:         end
66:       rescue PGError
67:         false
68:       end

    # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 48
48:       def adapter_name
49:         'PostgreSQL'
50:       end

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 303
303:       def add_column(table_name, column_name, type, options = {})
304:         native_type = native_database_types[type]
305:         sql_commands = ["ALTER TABLE #{table_name} ADD #{column_name} #{type_to_sql(type, options[:limit])}"]
306:         if options[:default]
307:           sql_commands << "ALTER TABLE #{table_name} ALTER #{column_name} SET DEFAULT '#{options[:default]}'"
308:         end
309:         if options[:null] == false
310:           sql_commands << "ALTER TABLE #{table_name} ALTER #{column_name} SET NOT NULL"
311:         end
312:         sql_commands.each { |cmd| execute(cmd) }
313:       end

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 228
228:       def default_sequence_name(table_name, pk = nil)
229:         default_pk, default_seq = pk_and_sequence_for(table_name)
230:         default_seq || "#{table_name}_#{pk || default_pk || 'id'}_seq"
231:       end

    # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 79
79:       def native_database_types
80:         {
81:           :primary_key => "serial primary key",
82:           :string      => { :name => "character varying", :limit => 255 },
83:           :text        => { :name => "text" },
84:           :integer     => { :name => "integer" },
85:           :float       => { :name => "float" },
86:           :datetime    => { :name => "timestamp" },
87:           :timestamp   => { :name => "timestamp" },
88:           :time        => { :name => "time" },
89:           :date        => { :name => "date" },
90:           :binary      => { :name => "bytea" },
91:           :boolean     => { :name => "boolean" }
92:         }
93:       end

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 253
253:       def pk_and_sequence_for(table)
254:         # First try looking for a sequence with a dependency on the
255:         # given table's primary key.
256:         result = execute("SELECT attr.attname, name.nspname, seq.relname\nFROM pg_class      seq,\npg_attribute  attr,\npg_depend     dep,\npg_namespace  name,\npg_constraint cons\nWHERE seq.oid           = dep.objid\nAND seq.relnamespace  = name.oid\nAND seq.relkind       = 'S'\nAND attr.attrelid     = dep.refobjid\nAND attr.attnum       = dep.refobjsubid\nAND attr.attrelid     = cons.conrelid\nAND attr.attnum       = cons.conkey[1]\nAND cons.contype      = 'p'\nAND dep.refobjid      = '\#{table}'::regclass\n", 'PK and serial sequence')[0]
257: 
258:         if result.nil? or result.empty?
259:           # If that fails, try parsing the primary key's default value.
260:           # Support the 7.x and 8.0 nextval('foo'::text) as well as
261:           # the 8.1+ nextval('foo'::regclass).
262:           # TODO: assumes sequence is in same schema as table.
263:           result = execute("SELECT attr.attname, name.nspname, split_part(def.adsrc, '\\\\\\'', 2)\nFROM pg_class       t\nJOIN pg_namespace   name ON (t.relnamespace = name.oid)\nJOIN pg_attribute   attr ON (t.oid = attrelid)\nJOIN pg_attrdef     def  ON (adrelid = attrelid AND adnum = attnum)\nJOIN pg_constraint  cons ON (conrelid = adrelid AND adnum = conkey[1])\nWHERE t.oid = '\#{table}'::regclass\nAND cons.contype = 'p'\nAND def.adsrc ~* 'nextval'\n", 'PK and custom sequence')[0]
264:         end
265:         # check for existence of . in sequence name as in public.foo_sequence.  if it does not exist, join the current namespace
266:         result.last['.'] ? [result.first, result.last] : [result.first, "#{result[1]}.#{result[2]}"]
267:       rescue
268:         nil
269:       end

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 102
102:       def quote(value, column = nil)
103:         if value.kind_of?(String) && column && column.type == :binary
104:           "'#{escape_bytea(value)}'"
105:         else
106:           super
107:         end
108:       end

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 110
110:       def quote_column_name(name)
111:         %("#{name}")
112:       end

    # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 71
71:       def reconnect!
72:         # TODO: postgres-pr doesn't have PGconn#reset.
73:         if @connection.respond_to?(:reset)
74:           @connection.reset
75:           configure_connection
76:         end
77:       end

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 299
299:       def rename_table(name, new_name)
300:         execute "ALTER TABLE #{name} RENAME TO #{new_name}"
301:       end

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 234
234:       def reset_pk_sequence!(table, pk = nil, sequence = nil)
235:         unless pk and sequence
236:           default_pk, default_sequence = pk_and_sequence_for(table)
237:           pk ||= default_pk
238:           sequence ||= default_sequence
239:         end
240:         if pk
241:           if sequence
242:             select_value "SELECT setval('\#{sequence}', (SELECT COALESCE(MAX(\#{pk})+(SELECT increment_by FROM \#{sequence}), (SELECT min_value FROM \#{sequence})) FROM \#{table}), false)\n", 'Reset sequence'
243:           else
244:             @logger.warn "#{table} has primary key #{pk} with no default sequence" if @logger
245:           end
246:         end
247:       end

    # File vendor/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 95
95:       def supports_migrations?
96:         true
97:       end