1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
|
# Make sure we're using pg high enough for type casts and Ruby 2.2+ compatibility
gem 'pg', '~> 0.18'
require 'pg'
require "active_record/connection_adapters/abstract_adapter"
require "active_record/connection_adapters/postgresql/column"
require "active_record/connection_adapters/postgresql/database_statements"
require "active_record/connection_adapters/postgresql/explain_pretty_printer"
require "active_record/connection_adapters/postgresql/oid"
require "active_record/connection_adapters/postgresql/quoting"
require "active_record/connection_adapters/postgresql/referential_integrity"
require "active_record/connection_adapters/postgresql/schema_definitions"
require "active_record/connection_adapters/postgresql/schema_dumper"
require "active_record/connection_adapters/postgresql/schema_statements"
require "active_record/connection_adapters/postgresql/type_metadata"
require "active_record/connection_adapters/postgresql/utils"
require "active_record/connection_adapters/statement_pool"
module ActiveRecord
module ConnectionHandling # :nodoc:
# Establishes a connection to the database that's used by all Active Record objects
def postgresql_connection(config)
conn_params = config.symbolize_keys
conn_params.delete_if { |_, v| v.nil? }
# Map ActiveRecords param names to PGs.
conn_params[:user] = conn_params.delete(:username) if conn_params[:username]
conn_params[:dbname] = conn_params.delete(:database) if conn_params[:database]
# Forward only valid config params to PGconn.connect.
valid_conn_param_keys = PGconn.conndefaults_hash.keys + [:requiressl]
conn_params.slice!(*valid_conn_param_keys)
# The postgres drivers don't allow the creation of an unconnected PGconn object,
# so just pass a nil connection object for the time being.
ConnectionAdapters::PostgreSQLAdapter.new(nil, logger, conn_params, config)
end
end
module ConnectionAdapters
# The PostgreSQL adapter works with the native C (https://bitbucket.org/ged/ruby-pg) driver.
#
# Options:
#
# * <tt>:host</tt> - Defaults to a Unix-domain socket in /tmp. On machines without Unix-domain sockets,
# the default is to connect to localhost.
# * <tt>:port</tt> - Defaults to 5432.
# * <tt>:username</tt> - Defaults to be the same as the operating system name of the user running the application.
# * <tt>:password</tt> - Password to be used if the server demands password authentication.
# * <tt>:database</tt> - Defaults to be the same as the user name.
# * <tt>:schema_search_path</tt> - An optional schema search path for the connection given
# as a string of comma-separated schema names. This is backward-compatible with the <tt>:schema_order</tt> option.
# * <tt>:encoding</tt> - An optional client encoding that is used in a <tt>SET client_encoding TO
# <encoding></tt> call on the connection.
# * <tt>:min_messages</tt> - An optional client min messages that is used in a
# <tt>SET client_min_messages TO <min_messages></tt> call on the connection.
# * <tt>:variables</tt> - An optional hash of additional parameters that
# will be used in <tt>SET SESSION key = val</tt> calls on the connection.
# * <tt>:insert_returning</tt> - An optional boolean to control the use of <tt>RETURNING</tt> for <tt>INSERT</tt> statements
# defaults to true.
#
# Any further options are used as connection parameters to libpq. See
# http://www.postgresql.org/docs/current/static/libpq-connect.html for the
# list of parameters.
#
# In addition, default connection parameters of libpq can be set per environment variables.
# See http://www.postgresql.org/docs/current/static/libpq-envars.html .
class PostgreSQLAdapter < AbstractAdapter
ADAPTER_NAME = 'PostgreSQL'.freeze
NATIVE_DATABASE_TYPES = {
primary_key: "serial primary key",
string: { name: "character varying" },
text: { name: "text" },
integer: { name: "integer" },
float: { name: "float" },
decimal: { name: "decimal" },
datetime: { name: "timestamp" },
time: { name: "time" },
date: { name: "date" },
daterange: { name: "daterange" },
numrange: { name: "numrange" },
tsrange: { name: "tsrange" },
tstzrange: { name: "tstzrange" },
int4range: { name: "int4range" },
int8range: { name: "int8range" },
binary: { name: "bytea" },
boolean: { name: "boolean" },
xml: { name: "xml" },
tsvector: { name: "tsvector" },
hstore: { name: "hstore" },
inet: { name: "inet" },
cidr: { name: "cidr" },
macaddr: { name: "macaddr" },
uuid: { name: "uuid" },
json: { name: "json" },
jsonb: { name: "jsonb" },
ltree: { name: "ltree" },
citext: { name: "citext" },
point: { name: "point" },
line: { name: "line" },
lseg: { name: "lseg" },
box: { name: "box" },
path: { name: "path" },
polygon: { name: "polygon" },
circle: { name: "circle" },
bit: { name: "bit" },
bit_varying: { name: "bit varying" },
money: { name: "money" },
}
OID = PostgreSQL::OID #:nodoc:
include PostgreSQL::Quoting
include PostgreSQL::ReferentialIntegrity
include PostgreSQL::SchemaStatements
include PostgreSQL::DatabaseStatements
include PostgreSQL::ColumnDumper
def schema_creation # :nodoc:
PostgreSQL::SchemaCreation.new self
end
def arel_visitor # :nodoc:
Arel::Visitors::PostgreSQL.new(self)
end
# Returns true, since this connection adapter supports prepared statement
# caching.
def supports_statement_cache?
true
end
def supports_index_sort_order?
true
end
def supports_partial_index?
true
end
def supports_expression_index?
true
end
def supports_transaction_isolation?
true
end
def supports_foreign_keys?
true
end
def supports_views?
true
end
def supports_datetime_with_precision?
true
end
def supports_json?
postgresql_version >= 90200
end
def supports_comments?
true
end
def supports_savepoints?
true
end
def index_algorithms
{ concurrently: 'CONCURRENTLY' }
end
class StatementPool < ConnectionAdapters::StatementPool
def initialize(connection, max)
super(max)
@connection = connection
@counter = 0
end
def next_key
"a#{@counter + 1}"
end
def []=(sql, key)
super.tap { @counter += 1 }
end
private
def dealloc(key)
@connection.query "DEALLOCATE #{key}" if connection_active?
end
def connection_active?
@connection.status == PGconn::CONNECTION_OK
rescue PGError
false
end
end
# Initializes and connects a PostgreSQL adapter.
def initialize(connection, logger, connection_parameters, config)
super(connection, logger, config)
@connection_parameters = connection_parameters
# @local_tz is initialized as nil to avoid warnings when connect tries to use it
@local_tz = nil
@table_alias_length = nil
connect
add_pg_encoders
@statements = StatementPool.new @connection,
self.class.type_cast_config_to_integer(config[:statement_limit])
if postgresql_version < 90100
raise "Your version of PostgreSQL (#{postgresql_version}) is too old. Active Record supports PostgreSQL >= 9.1."
end
add_pg_decoders
@type_map = Type::HashLookupTypeMap.new
initialize_type_map(type_map)
@local_tz = execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
@use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : true
end
# Clears the prepared statements cache.
def clear_cache!
@statements.clear
end
def truncate(table_name, name = nil)
exec_query "TRUNCATE TABLE #{quote_table_name(table_name)}", name, []
end
# Is this connection alive and ready for queries?
def active?
@connection.query 'SELECT 1'
true
rescue PGError
false
end
# Close then reopen the connection.
def reconnect!
super
@connection.reset
configure_connection
end
def reset!
clear_cache!
reset_transaction
unless @connection.transaction_status == ::PG::PQTRANS_IDLE
@connection.query 'ROLLBACK'
end
@connection.query 'DISCARD ALL'
configure_connection
end
# Disconnects from the database if already connected. Otherwise, this
# method does nothing.
def disconnect!
super
@connection.close rescue nil
end
def native_database_types #:nodoc:
NATIVE_DATABASE_TYPES
end
# Returns true, since this connection adapter supports migrations.
def supports_migrations?
true
end
# Does PostgreSQL support finding primary key on non-Active Record tables?
def supports_primary_key? #:nodoc:
true
end
def set_standard_conforming_strings
execute('SET standard_conforming_strings = on', 'SCHEMA')
end
def supports_ddl_transactions?
true
end
def supports_advisory_locks?
true
end
def supports_explain?
true
end
def supports_extensions?
true
end
# Range datatypes weren't introduced until PostgreSQL 9.2
def supports_ranges?
postgresql_version >= 90200
end
def supports_materialized_views?
postgresql_version >= 90300
end
def get_advisory_lock(lock_id) # :nodoc:
unless lock_id.is_a?(Integer) && lock_id.bit_length <= 63
raise(ArgumentError, "Postgres requires advisory lock ids to be a signed 64 bit integer")
end
select_value("SELECT pg_try_advisory_lock(#{lock_id});")
end
def release_advisory_lock(lock_id) # :nodoc:
unless lock_id.is_a?(Integer) && lock_id.bit_length <= 63
raise(ArgumentError, "Postgres requires advisory lock ids to be a signed 64 bit integer")
end
select_value("SELECT pg_advisory_unlock(#{lock_id})")
end
def enable_extension(name)
exec_query("CREATE EXTENSION IF NOT EXISTS \"#{name}\"").tap {
reload_type_map
}
end
def disable_extension(name)
exec_query("DROP EXTENSION IF EXISTS \"#{name}\" CASCADE").tap {
reload_type_map
}
end
def extension_enabled?(name)
if supports_extensions?
res = exec_query "SELECT EXISTS(SELECT * FROM pg_available_extensions WHERE name = '#{name}' AND installed_version IS NOT NULL) as enabled",
'SCHEMA'
res.cast_values.first
end
end
def extensions
if supports_extensions?
exec_query("SELECT extname from pg_extension", "SCHEMA").cast_values
else
super
end
end
# Returns the configured supported identifier length supported by PostgreSQL
def table_alias_length
@table_alias_length ||= query('SHOW max_identifier_length', 'SCHEMA')[0][0].to_i
end
# Set the authorized user for this session
def session_auth=(user)
clear_cache!
exec_query "SET SESSION AUTHORIZATION #{user}"
end
def use_insert_returning?
@use_insert_returning
end
def valid_type?(type)
!native_database_types[type].nil?
end
def update_table_definition(table_name, base) #:nodoc:
PostgreSQL::Table.new(table_name, base)
end
def lookup_cast_type(sql_type) # :nodoc:
oid = execute("SELECT #{quote(sql_type)}::regtype::oid", "SCHEMA").first['oid'].to_i
super(oid)
end
def column_name_for_operation(operation, node) # :nodoc:
OPERATION_ALIASES.fetch(operation) { operation.downcase }
end
OPERATION_ALIASES = { # :nodoc:
"maximum" => "max",
"minimum" => "min",
"average" => "avg",
}
# Returns the version of the connected PostgreSQL server.
def postgresql_version
@connection.server_version
end
protected
# See http://www.postgresql.org/docs/current/static/errcodes-appendix.html
VALUE_LIMIT_VIOLATION = "22001"
FOREIGN_KEY_VIOLATION = "23503"
UNIQUE_VIOLATION = "23505"
SERIALIZATION_FAILURE = "40001"
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)
when FOREIGN_KEY_VIOLATION
InvalidForeignKey.new(message)
when VALUE_LIMIT_VIOLATION
ValueTooLong.new(message)
when SERIALIZATION_FAILURE
TransactionSerializationError.new(message)
else
super
end
end
private
def get_oid_type(oid, fmod, column_name, sql_type = '') # :nodoc:
if !type_map.key?(oid)
load_additional_types(type_map, [oid])
end
type_map.fetch(oid, fmod, sql_type) {
warn "unknown OID #{oid}: failed to recognize type of '#{column_name}'. It will be treated as String."
Type::Value.new.tap do |cast_type|
type_map.register_type(oid, cast_type)
end
}
end
def initialize_type_map(m) # :nodoc:
register_class_with_limit m, 'int2', Type::Integer
register_class_with_limit m, 'int4', Type::Integer
register_class_with_limit m, 'int8', Type::Integer
m.alias_type 'oid', 'int2'
m.register_type 'float4', Type::Float.new
m.alias_type 'float8', 'float4'
m.register_type 'text', Type::Text.new
register_class_with_limit m, 'varchar', Type::String
m.alias_type 'char', 'varchar'
m.alias_type 'name', 'varchar'
m.alias_type 'bpchar', 'varchar'
m.register_type 'bool', Type::Boolean.new
register_class_with_limit m, 'bit', OID::Bit
register_class_with_limit m, 'varbit', OID::BitVarying
m.alias_type 'timestamptz', 'timestamp'
m.register_type 'date', Type::Date.new
m.register_type 'money', OID::Money.new
m.register_type 'bytea', OID::Bytea.new
m.register_type 'point', OID::Point.new
m.register_type 'hstore', OID::Hstore.new
m.register_type 'json', OID::Json.new
m.register_type 'jsonb', OID::Jsonb.new
m.register_type 'cidr', OID::Cidr.new
m.register_type 'inet', OID::Inet.new
m.register_type 'uuid', OID::Uuid.new
m.register_type 'xml', OID::Xml.new
m.register_type 'tsvector', OID::SpecializedString.new(:tsvector)
m.register_type 'macaddr', OID::SpecializedString.new(:macaddr)
m.register_type 'citext', OID::SpecializedString.new(:citext)
m.register_type 'ltree', OID::SpecializedString.new(:ltree)
m.register_type 'line', OID::SpecializedString.new(:line)
m.register_type 'lseg', OID::SpecializedString.new(:lseg)
m.register_type 'box', OID::SpecializedString.new(:box)
m.register_type 'path', OID::SpecializedString.new(:path)
m.register_type 'polygon', OID::SpecializedString.new(:polygon)
m.register_type 'circle', OID::SpecializedString.new(:circle)
# FIXME: why are we keeping these types as strings?
m.alias_type 'interval', 'varchar'
register_class_with_precision m, 'time', Type::Time
register_class_with_precision m, 'timestamp', OID::DateTime
m.register_type 'numeric' do |_, fmod, sql_type|
precision = extract_precision(sql_type)
scale = extract_scale(sql_type)
# The type for the numeric depends on the width of the field,
# so we'll do something special here.
#
# When dealing with decimal columns:
#
# places after decimal = fmod - 4 & 0xffff
# places before decimal = (fmod - 4) >> 16 & 0xffff
if fmod && (fmod - 4 & 0xffff).zero?
# FIXME: Remove this class, and the second argument to
# lookups on PG
Type::DecimalWithoutScale.new(precision: precision)
else
OID::Decimal.new(precision: precision, scale: scale)
end
end
load_additional_types(m)
end
def extract_limit(sql_type) # :nodoc:
case sql_type
when /^bigint/i, /^int8/i
8
when /^smallint/i
2
else
super
end
end
# Extracts the value from a PostgreSQL column default definition.
def extract_value_from_default(default) # :nodoc:
case default
# Quoted types
when /\A[\(B]?'(.*)'.*::"?([\w. ]+)"?(?:\[\])?\z/m
# The default 'now'::date is CURRENT_DATE
if $1 == "now".freeze && $2 == "date".freeze
nil
else
$1.gsub("''".freeze, "'".freeze)
end
# Boolean types
when 'true'.freeze, 'false'.freeze
default
# Numeric types
when /\A\(?(-?\d+(\.\d*)?)\)?(::bigint)?\z/
$1
# Object identifier types
when /\A-?\d+\z/
$1
else
# Anything else is blank, some user type, or some function
# and we can't know the value of that, so return nil.
nil
end
end
def extract_default_function(default_value, default) # :nodoc:
default if has_default_function?(default_value, default)
end
def has_default_function?(default_value, default) # :nodoc:
!default_value && (%r{\w+\(.*\)|\(.*\)::\w+} === default)
end
def load_additional_types(type_map, oids = nil) # :nodoc:
initializer = OID::TypeMapInitializer.new(type_map)
if supports_ranges?
query = <<-SQL
SELECT t.oid, t.typname, t.typelem, t.typdelim, t.typinput, r.rngsubtype, t.typtype, t.typbasetype
FROM pg_type as t
LEFT JOIN pg_range as r ON oid = rngtypid
SQL
else
query = <<-SQL
SELECT t.oid, t.typname, t.typelem, t.typdelim, t.typinput, t.typtype, t.typbasetype
FROM pg_type as t
SQL
end
if oids
query += "WHERE t.oid::integer IN (%s)" % oids.join(", ")
else
query += initializer.query_conditions_for_initial_load(type_map)
end
execute_and_clear(query, 'SCHEMA', []) do |records|
initializer.run(records)
end
end
FEATURE_NOT_SUPPORTED = "0A000" #:nodoc:
def execute_and_clear(sql, name, binds, prepare: false)
if without_prepared_statement?(binds)
result = exec_no_cache(sql, name, [])
elsif !prepare
result = exec_no_cache(sql, name, binds)
else
result = exec_cache(sql, name, binds)
end
ret = yield result
result.clear
ret
end
def exec_no_cache(sql, name, binds)
type_casted_binds = binds.map { |attr| type_cast(attr.value_for_database) }
log(sql, name, binds) { @connection.async_exec(sql, type_casted_binds) }
end
def exec_cache(sql, name, binds)
stmt_key = prepare_statement(sql)
type_casted_binds = binds.map { |attr| type_cast(attr.value_for_database) }
log(sql, name, binds, stmt_key) do
@connection.exec_prepared(stmt_key, type_casted_binds)
end
rescue ActiveRecord::StatementInvalid => e
raise unless is_cached_plan_failure?(e)
# Nothing we can do if we are in a transaction because all commands
# will raise InFailedSQLTransaction
if in_transaction?
raise ActiveRecord::PreparedStatementCacheExpired.new(e.cause.message)
else
# outside of transactions we can simply flush this query and retry
@statements.delete sql_key(sql)
retry
end
end
# Annoyingly, the code for prepared statements whose return value may
# have changed is FEATURE_NOT_SUPPORTED.
#
# This covers various different error types so we need to do additional
# work to classify the exception definitively as a
# ActiveRecord::PreparedStatementCacheExpired
#
# Check here for more details:
# http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/utils/cache/plancache.c#l573
CACHED_PLAN_HEURISTIC = 'cached plan must not change result type'.freeze
def is_cached_plan_failure?(e)
pgerror = e.cause
code = pgerror.result.result_error_field(PGresult::PG_DIAG_SQLSTATE)
code == FEATURE_NOT_SUPPORTED && pgerror.message.include?(CACHED_PLAN_HEURISTIC)
rescue
false
end
def in_transaction?
open_transactions > 0
end
# Returns the statement identifier for the client side cache
# of statements
def sql_key(sql)
"#{schema_search_path}-#{sql}"
end
# Prepare the statement if it hasn't been prepared, return
# the statement key.
def prepare_statement(sql)
sql_key = sql_key(sql)
unless @statements.key? sql_key
nextkey = @statements.next_key
begin
@connection.prepare nextkey, sql
rescue => e
raise translate_exception_class(e, sql)
end
# Clear the queue
@connection.get_last_result
@statements[sql_key] = nextkey
end
@statements[sql_key]
end
# Connects to a PostgreSQL server and sets up the adapter depending on the
# connected server's characteristics.
def connect
@connection = PGconn.connect(@connection_parameters)
configure_connection
rescue ::PG::Error => error
if error.message.include?("does not exist")
raise ActiveRecord::NoDatabaseError
else
raise
end
end
# Configures the encoding, verbosity, schema search path, and time zone of the connection.
# This is called by #connect and should not be called manually.
def configure_connection
if @config[:encoding]
@connection.set_client_encoding(@config[:encoding])
end
self.client_min_messages = @config[:min_messages] || 'warning'
self.schema_search_path = @config[:schema_search_path] || @config[:schema_order]
# Use standard-conforming strings so we don't have to do the E'...' dance.
set_standard_conforming_strings
# If using Active Record's time zone support configure the connection to return
# TIMESTAMP WITH ZONE types in UTC.
# (SET TIME ZONE does not use an equals sign like other SET variables)
if ActiveRecord::Base.default_timezone == :utc
execute("SET time zone 'UTC'", 'SCHEMA')
elsif @local_tz
execute("SET time zone '#{@local_tz}'", 'SCHEMA')
end
# SET statements from :variables config hash
# http://www.postgresql.org/docs/current/static/sql-set.html
variables = @config[:variables] || {}
variables.map do |k, v|
if v == ':default' || v == :default
# Sets the value to the global or compile default
execute("SET SESSION #{k} TO DEFAULT", 'SCHEMA')
elsif !v.nil?
execute("SET SESSION #{k} TO #{quote(v)}", 'SCHEMA')
end
end
end
# Returns the current ID of a table's sequence.
def last_insert_id_result(sequence_name) # :nodoc:
exec_query("SELECT currval('#{sequence_name}')", 'SQL')
end
# Returns the list of a table's column names, data types, and default values.
#
# The underlying query is roughly:
# SELECT column.name, column.type, default.value, column.comment
# FROM column LEFT JOIN default
# ON column.table_id = default.table_id
# AND column.num = default.column_num
# WHERE column.table_id = get_table_id('table_name')
# AND column.num > 0
# AND NOT column.is_dropped
# ORDER BY column.num
#
# If the table name is not prefixed with a schema, the database will
# take the first match from the schema search path.
#
# Query implementation notes:
# - format_type includes the column size constraint, e.g. varchar(50)
# - ::regclass is a function that gives the id for a table name
def column_definitions(table_name) # :nodoc:
query(<<-end_sql, 'SCHEMA')
SELECT a.attname, format_type(a.atttypid, a.atttypmod),
pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod,
(SELECT c.collname FROM pg_collation c, pg_type t
WHERE c.oid = a.attcollation AND t.oid = a.atttypid AND a.attcollation <> t.typcollation),
col_description(a.attrelid, a.attnum) AS comment
FROM pg_attribute a LEFT JOIN pg_attrdef d
ON a.attrelid = d.adrelid AND a.attnum = d.adnum
WHERE a.attrelid = '#{quote_table_name(table_name)}'::regclass
AND a.attnum > 0 AND NOT a.attisdropped
ORDER BY a.attnum
end_sql
end
def extract_table_ref_from_insert_sql(sql) # :nodoc:
sql[/into\s("[A-Za-z0-9_."\[\]\s]+"|[A-Za-z0-9_."\[\]]+)\s*/im]
$1.strip if $1
end
def create_table_definition(*args) # :nodoc:
PostgreSQL::TableDefinition.new(*args)
end
def can_perform_case_insensitive_comparison_for?(column)
@case_insensitive_cache ||= {}
@case_insensitive_cache[column.sql_type] ||= begin
sql = <<-end_sql
SELECT exists(
SELECT * FROM pg_proc
INNER JOIN pg_cast
ON casttarget::text::oidvector = proargtypes
WHERE proname = 'lower'
AND castsource = '#{column.sql_type}'::regtype::oid
)
end_sql
execute_and_clear(sql, "SCHEMA", []) do |result|
result.getvalue(0, 0)
end
end
end
def add_pg_encoders
map = PG::TypeMapByClass.new
map[Integer] = PG::TextEncoder::Integer.new
map[TrueClass] = PG::TextEncoder::Boolean.new
map[FalseClass] = PG::TextEncoder::Boolean.new
map[Float] = PG::TextEncoder::Float.new
@connection.type_map_for_queries = map
end
def add_pg_decoders
coders_by_name = {
'int2' => PG::TextDecoder::Integer,
'int4' => PG::TextDecoder::Integer,
'int8' => PG::TextDecoder::Integer,
'oid' => PG::TextDecoder::Integer,
'float4' => PG::TextDecoder::Float,
'float8' => PG::TextDecoder::Float,
'bool' => PG::TextDecoder::Boolean,
}
known_coder_types = coders_by_name.keys.map { |n| quote(n) }
query = <<-SQL % known_coder_types.join(", ")
SELECT t.oid, t.typname
FROM pg_type as t
WHERE t.typname IN (%s)
SQL
coders = execute_and_clear(query, "SCHEMA", []) do |result|
result
.map { |row| construct_coder(row, coders_by_name[row['typname']]) }
.compact
end
map = PG::TypeMapByOid.new
coders.each { |coder| map.add_coder(coder) }
@connection.type_map_for_results = map
end
def construct_coder(row, coder_class)
return unless coder_class
coder_class.new(oid: row['oid'].to_i, name: row['typname'])
end
ActiveRecord::Type.add_modifier({ array: true }, OID::Array, adapter: :postgresql)
ActiveRecord::Type.add_modifier({ range: true }, OID::Range, adapter: :postgresql)
ActiveRecord::Type.register(:bit, OID::Bit, adapter: :postgresql)
ActiveRecord::Type.register(:bit_varying, OID::BitVarying, adapter: :postgresql)
ActiveRecord::Type.register(:binary, OID::Bytea, adapter: :postgresql)
ActiveRecord::Type.register(:cidr, OID::Cidr, adapter: :postgresql)
ActiveRecord::Type.register(:datetime, OID::DateTime, adapter: :postgresql)
ActiveRecord::Type.register(:decimal, OID::Decimal, adapter: :postgresql)
ActiveRecord::Type.register(:enum, OID::Enum, adapter: :postgresql)
ActiveRecord::Type.register(:hstore, OID::Hstore, adapter: :postgresql)
ActiveRecord::Type.register(:inet, OID::Inet, adapter: :postgresql)
ActiveRecord::Type.register(:json, OID::Json, adapter: :postgresql)
ActiveRecord::Type.register(:jsonb, OID::Jsonb, adapter: :postgresql)
ActiveRecord::Type.register(:money, OID::Money, adapter: :postgresql)
ActiveRecord::Type.register(:point, OID::Rails51Point, adapter: :postgresql)
ActiveRecord::Type.register(:legacy_point, OID::Point, adapter: :postgresql)
ActiveRecord::Type.register(:uuid, OID::Uuid, adapter: :postgresql)
ActiveRecord::Type.register(:vector, OID::Vector, adapter: :postgresql)
ActiveRecord::Type.register(:xml, OID::Xml, adapter: :postgresql)
end
end
end
|