Class Sequel::Postgres::Database
In: lib/sequel/adapters/postgres.rb
Parent: Sequel::Database

Methods

Included Modules

Sequel::Postgres::DatabaseMethods

Constants

INFINITE_TIMESTAMP_STRINGS = ['infinity'.freeze, '-infinity'.freeze].freeze
INFINITE_DATETIME_VALUES = ([PLUS_INFINITY, MINUS_INFINITY] + INFINITE_TIMESTAMP_STRINGS).freeze
DATABASE_ERROR_CLASSES = [PGError].freeze

Attributes

convert_infinite_timestamps  [R]  Whether infinite timestamps/dates should be converted on retrieval. By default, no conversion is done, so an error is raised if you attempt to retrieve an infinite timestamp/date. You can set this to :nil to convert to nil, :string to leave as a string, or :float to convert to an infinite float.

Public Instance methods

Convert given argument so that it can be used directly by pg. Currently, pg doesn‘t handle fractional seconds in Time/DateTime or blobs with "\0". Only public for use by the adapter, shouldn‘t be used by external code.

[Source]

     # File lib/sequel/adapters/postgres.rb, line 167
167:       def bound_variable_arg(arg, conn)
168:         case arg
169:         when Sequel::SQL::Blob
170:           {:value=>arg, :type=>17, :format=>1}
171:         when DateTime, Time
172:           literal(arg)
173:         else
174:           arg
175:         end
176:       end

Connects to the database. In addition to the standard database options, using the :encoding or :charset option changes the client encoding for the connection, :connect_timeout is a connection timeout in seconds, :sslmode sets whether postgres‘s sslmode, and :notice_receiver handles server notices in a proc. :connect_timeout, :driver_options, :sslmode, and :notice_receiver are only supported if the pg driver is used.

[Source]

     # File lib/sequel/adapters/postgres.rb, line 185
185:       def connect(server)
186:         opts = server_opts(server)
187:         if USES_PG
188:           connection_params = {
189:             :host => opts[:host],
190:             :port => opts[:port] || 5432,
191:             :dbname => opts[:database],
192:             :user => opts[:user],
193:             :password => opts[:password],
194:             :connect_timeout => opts[:connect_timeout] || 20,
195:             :sslmode => opts[:sslmode],
196:             :sslrootcert => opts[:sslrootcert]
197:           }.delete_if { |key, value| blank_object?(value) }
198:           connection_params.merge!(opts[:driver_options]) if opts[:driver_options]
199:           conn = Adapter.connect(connection_params)
200: 
201:           conn.instance_variable_set(:@prepared_statements, {})
202: 
203:           if receiver = opts[:notice_receiver]
204:             conn.set_notice_receiver(&receiver)
205:           end
206:         else
207:           unless typecast_value_boolean(@opts.fetch(:force_standard_strings, true))
208:             raise Error, "Cannot create connection using postgres-pr unless force_standard_strings is set"
209:           end
210: 
211:           conn = Adapter.connect(
212:             (opts[:host] unless blank_object?(opts[:host])),
213:             opts[:port] || 5432,
214:             nil, '',
215:             opts[:database],
216:             opts[:user],
217:             opts[:password]
218:           )
219:         end
220: 
221:         conn.instance_variable_set(:@db, self)
222: 
223:         if encoding = opts[:encoding] || opts[:charset]
224:           if conn.respond_to?(:set_client_encoding)
225:             conn.set_client_encoding(encoding)
226:           else
227:             conn.async_exec("set client_encoding to '#{encoding}'")
228:           end
229:         end
230: 
231:         connection_configuration_sqls.each{|sql| conn.execute(sql)}
232:         conn
233:       end

Set whether to allow infinite timestamps/dates. Make sure the conversion proc for date reflects that setting.

[Source]

     # File lib/sequel/adapters/postgres.rb, line 237
237:       def convert_infinite_timestamps=(v)
238:         @convert_infinite_timestamps = case v
239:         when Symbol
240:           v
241:         when 'nil'
242:           :nil
243:         when 'string'
244:           :string
245:         when 'float'
246:           :float
247:         when String
248:           typecast_value_boolean(v)
249:         else
250:           false
251:         end
252: 
253:         pr = old_pr = @use_iso_date_format ? TYPE_TRANSLATOR.method(:date) : Sequel.method(:string_to_date)
254:         if v
255:           pr = lambda do |val|
256:             case val
257:             when *INFINITE_TIMESTAMP_STRINGS
258:               infinite_timestamp_value(val)
259:             else
260:               old_pr.call(val)
261:             end
262:           end
263:         end
264:         add_conversion_proc(1082, pr)
265:       end

copy_into uses PostgreSQL‘s +COPY FROM STDIN+ SQL statement to do very fast inserts into a table using input preformatting in either CSV or PostgreSQL text format. This method is only supported if pg 0.14.0+ is the underlying ruby driver. This method should only be called if you want results returned to the client. If you are using +COPY FROM+ with a filename, you should just use run instead of this method.

The following options are respected:

:columns :The columns to insert into, with the same order as the columns in the input data. If this isn‘t given, uses all columns in the table.
:data :The data to copy to PostgreSQL, which should already be in CSV or PostgreSQL text format. This can be either a string, or any object that responds to each and yields string.
:format :The format to use. text is the default, so this should be :csv or :binary.
:options :An options SQL string to use, which should contain comma separated options.
:server :The server on which to run the query.

If a block is provided and :data option is not, this will yield to the block repeatedly. The block should return a string, or nil to signal that it is finished.

[Source]

     # File lib/sequel/adapters/postgres.rb, line 371
371:         def copy_into(table, opts=OPTS)
372:           data = opts[:data]
373:           data = Array(data) if data.is_a?(String)
374: 
375:           if block_given? && data
376:             raise Error, "Cannot provide both a :data option and a block to copy_into"
377:           elsif !block_given? && !data
378:             raise Error, "Must provide either a :data option or a block to copy_into"
379:           end
380: 
381:           synchronize(opts[:server]) do |conn|
382:             conn.execute(copy_into_sql(table, opts))
383:             begin
384:               if block_given?
385:                 while buf = yield
386:                   conn.put_copy_data(buf)
387:                 end
388:               else
389:                 data.each{|buff| conn.put_copy_data(buff)}
390:               end
391:             rescue Exception => e
392:               conn.put_copy_end("ruby exception occurred while copying data into PostgreSQL")
393:             ensure
394:               conn.put_copy_end unless e
395:               while res = conn.get_result
396:                 raise e if e
397:                 check_database_errors{res.check}
398:               end
399:             end
400:           end 
401:         end

copy_table uses PostgreSQL‘s +COPY TO STDOUT+ SQL statement to return formatted results directly to the caller. This method is only supported if pg is the underlying ruby driver. This method should only be called if you want results returned to the client. If you are using +COPY TO+ with a filename, you should just use run instead of this method.

The table argument supports the following types:

String :Uses the first argument directly as literal SQL. If you are using a version of PostgreSQL before 9.0, you will probably want to use a string if you are using any options at all, as the syntax Sequel uses for options is only compatible with PostgreSQL 9.0+.
Dataset :Uses a query instead of a table name when copying.
other :Uses a table name (usually a symbol) when copying.

The following options are respected:

:format :The format to use. text is the default, so this should be :csv or :binary.
:options :An options SQL string to use, which should contain comma separated options.
:server :The server on which to run the query.

If a block is provided, the method continually yields to the block, one yield per row. If a block is not provided, a single string is returned with all of the data.

[Source]

     # File lib/sequel/adapters/postgres.rb, line 327
327:         def copy_table(table, opts=OPTS)
328:           synchronize(opts[:server]) do |conn|
329:             conn.execute(copy_table_sql(table, opts))
330:             begin
331:               if block_given?
332:                 while buf = conn.get_copy_data
333:                   yield buf
334:                 end
335:                 nil
336:               else
337:                 b = String.new
338:                 b << buf while buf = conn.get_copy_data
339:                 b
340:               end
341:             rescue => e
342:               raise_error(e, :disconnect=>true)
343:             ensure
344:               if buf && !e
345:                 raise DatabaseDisconnectError, "disconnecting as a partial COPY may leave the connection in an unusable state"
346:               end
347:             end
348:           end 
349:         end

[Source]

     # File lib/sequel/adapters/postgres.rb, line 267
267:       def disconnect_connection(conn)
268:         conn.finish
269:       rescue PGError, IOError
270:         nil
271:       end

Return a hash of information about the related PGError (or Sequel::DatabaseError that wraps a PGError), with the following entries:

:schema :The schema name related to the error
:table :The table name related to the error
:column :the column name related to the error
:constraint :The constraint name related to the error
:type :The datatype name related to the error

This requires a PostgreSQL 9.3+ server and 9.3+ client library, and ruby-pg 0.16.0+ to be supported.

[Source]

     # File lib/sequel/adapters/postgres.rb, line 285
285:         def error_info(e)
286:           e = e.wrapped_exception if e.is_a?(DatabaseError)
287:           r = e.result
288:           h = {}
289:           h[:schema] = r.error_field(::PG::PG_DIAG_SCHEMA_NAME)
290:           h[:table] = r.error_field(::PG::PG_DIAG_TABLE_NAME)
291:           h[:column] = r.error_field(::PG::PG_DIAG_COLUMN_NAME)
292:           h[:constraint] = r.error_field(::PG::PG_DIAG_CONSTRAINT_NAME)
293:           h[:type] = r.error_field(::PG::PG_DIAG_DATATYPE_NAME)
294:           h
295:         end

[Source]

     # File lib/sequel/adapters/postgres.rb, line 298
298:       def execute(sql, opts=OPTS, &block)
299:         synchronize(opts[:server]){|conn| check_database_errors{_execute(conn, sql, opts, &block)}}
300:       end

Listens on the given channel (or multiple channels if channel is an array), waiting for notifications. After a notification is received, or the timeout has passed, stops listening to the channel. Options:

:after_listen :An object that responds to call that is called with the underlying connection after the LISTEN statement is sent, but before the connection starts waiting for notifications.
:loop :Whether to continually wait for notifications, instead of just waiting for a single notification. If this option is given, a block must be provided. If this object responds to call, it is called with the underlying connection after each notification is received (after the block is called). If a :timeout option is used, and a callable object is given, the object will also be called if the timeout expires. If :loop is used and you want to stop listening, you can either break from inside the block given to listen, or you can throw :stop from inside the :loop object‘s call method or the block.
:server :The server on which to listen, if the sharding support is being used.
:timeout :How long to wait for a notification, in seconds (can provide a float value for fractional seconds). If this object responds to call, it will be called and should return the number of seconds to wait. If the loop option is also specified, the object will be called on each iteration to obtain a new timeout value. If not given or nil, waits indefinitely.

This method is only supported if pg is used as the underlying ruby driver. It returns the channel the notification was sent to (as a string), unless :loop was used, in which case it returns nil. If a block is given, it is yielded 3 arguments:

  • the channel the notification was sent to (as a string)
  • the backend pid of the notifier (as an integer),
  • and the payload of the notification (as a string or nil).

[Source]

     # File lib/sequel/adapters/postgres.rb, line 426
426:         def listen(channels, opts=OPTS, &block)
427:           check_database_errors do
428:             synchronize(opts[:server]) do |conn|
429:               begin
430:                 channels = Array(channels)
431:                 channels.each do |channel|
432:                   sql = "LISTEN ".dup
433:                   dataset.send(:identifier_append, sql, channel)
434:                   conn.execute(sql)
435:                 end
436:                 opts[:after_listen].call(conn) if opts[:after_listen]
437:                 timeout = opts[:timeout]
438:                 if timeout
439:                   timeout_block = timeout.respond_to?(:call) ? timeout : proc{timeout}
440:                 end
441: 
442:                 if l = opts[:loop]
443:                   raise Error, 'calling #listen with :loop requires a block' unless block
444:                   loop_call = l.respond_to?(:call)
445:                   catch(:stop) do
446:                     loop do
447:                       t = timeout_block ? [timeout_block.call] : []
448:                       conn.wait_for_notify(*t, &block)
449:                       l.call(conn) if loop_call
450:                     end
451:                   end
452:                   nil
453:                 else
454:                   t = timeout_block ? [timeout_block.call] : []
455:                   conn.wait_for_notify(*t, &block)
456:                 end
457:               ensure
458:                 conn.execute("UNLISTEN *")
459:               end
460:             end
461:           end
462:         end

If convert_infinite_timestamps is true and the value is infinite, return an appropriate value based on the convert_infinite_timestamps setting.

[Source]

     # File lib/sequel/adapters/postgres.rb, line 467
467:       def to_application_timestamp(value)
468:         if convert_infinite_timestamps
469:           case value
470:           when *INFINITE_TIMESTAMP_STRINGS
471:             infinite_timestamp_value(value)
472:           else
473:             super
474:           end
475:         else
476:           super
477:         end
478:       end

[Validate]