Class: ActiveRecord::ConnectionAdapters::AbstractAdapter

Inherits:
Object
  • Object
show all
Includes:
DatabaseLimits, DatabaseStatements, QueryCache, Quoting, Savepoints, SchemaStatements, ActiveSupport::Callbacks
Defined in:
activerecord/lib/active_record/connection_adapters/abstract_adapter.rb

Overview

Active Record supports multiple database systems. AbstractAdapter and related classes form the abstraction layer which makes this possible. An AbstractAdapter represents a connection to a database, and provides an abstract interface for database-specific functionality such as establishing a connection, escaping values, building the right SQL fragments for :offset and :limit options, etc.

All the concrete database adapters follow the interface laid down in this class. ActiveRecord::Base.connection returns an AbstractAdapter object, which you can use.

Most of the methods in the adapter are useful during migrations. Most notably, the instance methods provided by SchemaStatements are very useful.

Defined Under Namespace

Classes: Version

Constant Summary collapse

ADAPTER_NAME =
"Abstract"
SIMPLE_INT =
/\A\d+\z/
COMMENT_REGEX =
%r{/\*(?:[^\*]|\*[^/])*\*/}m

Constants included from ActiveSupport::Callbacks

ActiveSupport::Callbacks::CALLBACK_FILTER_TYPES

Instance Attribute Summary collapse

Attributes included from QueryCache

#query_cache, #query_cache_enabled

Attributes included from DatabaseStatements

#transaction_manager

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Savepoints

#create_savepoint, #current_savepoint_name, #exec_rollback_to_savepoint, #release_savepoint

Methods included from QueryCache

#cache, #clear_query_cache, dirties_query_cache, #disable_query_cache!, #enable_query_cache!, included, #select_all, #uncached

Methods included from DatabaseLimits

#allowed_index_name_length, #column_name_length, #columns_per_multicolumn_index, #columns_per_table, #in_clause_length, #index_name_length, #indexes_per_table, #joins_per_query, #max_identifier_length, #sql_query_length, #table_alias_length, #table_name_length

Methods included from Quoting

#column_name_matcher, #column_name_with_order_matcher, #lookup_cast_type_from_column, #quote, #quote_column_name, #quote_default_expression, #quote_string, #quote_table_name, #quote_table_name_for_assignment, #quoted_binary, #quoted_date, #quoted_false, #quoted_time, #quoted_true, #sanitize_as_sql_comment, #type_cast, #unquoted_false, #unquoted_true

Methods included from DatabaseStatements

#add_transaction_record, #begin_db_transaction, #begin_isolated_db_transaction, #cacheable_query, #commit_db_transaction, #default_sequence_name, #delete, #empty_insert_statement_value, #exec_delete, #exec_insert, #exec_insert_all, #exec_query, #exec_rollback_db_transaction, #exec_update, #execute, #insert, #insert_fixture, #insert_fixtures_set, #mark_transaction_written_if_write, #query, #query_value, #query_values, #reset_sequence!, #reset_transaction, #rollback_db_transaction, #rollback_to_savepoint, #sanitize_limit, #select_all, #select_one, #select_rows, #select_value, #select_values, #to_sql, #transaction, #transaction_isolation_levels, #transaction_open?, #truncate, #truncate_tables, #update, #with_yaml_fallback, #write_query?

Methods included from SchemaStatements

#add_check_constraint, #add_column, #add_columns, #add_foreign_key, #add_index, #add_index_options, #add_reference, #add_timestamps, #assume_migrated_upto_version, #change_column, #change_column_comment, #change_column_default, #change_column_null, #change_table, #change_table_comment, #check_constraint_options, #check_constraints, #column_exists?, #columns, #columns_for_distinct, #create_join_table, #create_schema_dumper, #create_table, #data_source_exists?, #data_sources, #drop_join_table, #drop_table, #dump_schema_information, #foreign_key_column_for, #foreign_key_exists?, #foreign_key_options, #foreign_keys, #index_algorithm, #index_exists?, #index_name, #index_name_exists?, #indexes, #internal_string_options_for_primary_key, #native_database_types, #options_include_default?, #primary_key, #quoted_columns_for_index, #remove_check_constraint, #remove_column, #remove_columns, #remove_foreign_key, #remove_index, #remove_reference, #remove_timestamps, #rename_column, #rename_index, #rename_table, #table_alias_for, #table_comment, #table_exists?, #table_options, #tables, #type_to_sql, #update_table_definition, #view_exists?, #views

Methods included from ActiveSupport::Callbacks

#run_callbacks

Methods included from ActiveSupport::Concern

#append_features, #class_methods, extended, #included, #prepend_features, #prepended

Constructor Details

#initialize(connection, logger = nil, config = {}) ⇒ AbstractAdapter

:nodoc:


83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 83

def initialize(connection, logger = nil, config = {}) # :nodoc:
  super()

  @connection          = connection
  @owner               = nil
  @instrumenter        = ActiveSupport::Notifications.instrumenter
  @logger              = logger
  @config              = config
  @pool                = ActiveRecord::ConnectionAdapters::NullPool.new
  @idle_since          = Concurrent.monotonic_time
  @visitor = arel_visitor
  @statements = build_statement_pool
  @lock = ActiveSupport::Concurrency::LoadInterlockAwareMonitor.new

  @prepared_statements = self.class.type_cast_config_to_boolean(
    config.fetch(:prepared_statements, true)
  )

  @advisory_locks_enabled = self.class.type_cast_config_to_boolean(
    config.fetch(:advisory_locks, true)
  )
end

Instance Attribute Details

#lockObject (readonly)

Returns the value of attribute lock


43
44
45
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 43

def lock
  @lock
end

#loggerObject (readonly)

Returns the value of attribute logger


43
44
45
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 43

def logger
  @logger
end

#ownerObject (readonly) Also known as: in_use?

Returns the value of attribute owner


43
44
45
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 43

def owner
  @owner
end

#poolObject

Returns the value of attribute pool


42
43
44
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 42

def pool
  @pool
end

#visitorObject (readonly)

Returns the value of attribute visitor


43
44
45
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 43

def visitor
  @visitor
end

Class Method Details

.build_read_query_regexp(*parts) ⇒ Object

:nodoc:


69
70
71
72
73
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 69

def self.build_read_query_regexp(*parts) # :nodoc:
  parts += DEFAULT_READ_QUERY
  parts = parts.map { |part| /#{part}/i }
  /\A(?:[\(\s]|#{COMMENT_REGEX})*#{Regexp.union(*parts)}/
end

.database_exists?(config) ⇒ Boolean

Does the database for this adapter exist?

Returns:

  • (Boolean)

Raises:

  • (NotImplementedError)

253
254
255
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 253

def self.database_exists?(config)
  raise NotImplementedError
end

.quoted_column_namesObject

:nodoc:


75
76
77
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 75

def self.quoted_column_names # :nodoc:
  @quoted_column_names ||= {}
end

.quoted_table_namesObject

:nodoc:


79
80
81
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 79

def self.quoted_table_names # :nodoc:
  @quoted_table_names ||= {}
end

.type_cast_config_to_boolean(config) ⇒ Object


58
59
60
61
62
63
64
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 58

def self.type_cast_config_to_boolean(config)
  if config == "false"
    false
  else
    config
  end
end

.type_cast_config_to_integer(config) ⇒ Object


48
49
50
51
52
53
54
55
56
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 48

def self.type_cast_config_to_integer(config)
  if config.is_a?(Integer)
    config
  elsif SIMPLE_INT.match?(config)
    config.to_i
  else
    config
  end
end

Instance Method Details

#active?Boolean

Checks whether the connection to the database is still active. This includes checking whether the database is actually capable of responding, i.e. whether the connection isn't stale.

Returns:

  • (Boolean)

469
470
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 469

def active?
end

#adapter_nameObject

Returns the human-readable name of the adapter. Use mixed case - one can always use downcase if needed.


248
249
250
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 248

def adapter_name
  self.class::ADAPTER_NAME
end

#advisory_locks_enabled?Boolean

:nodoc:

Returns:

  • (Boolean)

429
430
431
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 429

def advisory_locks_enabled? # :nodoc:
  supports_advisory_locks? && @advisory_locks_enabled
end

#build_insert_sql(insert) ⇒ Object

Called by ActiveRecord::InsertAll, Passed an instance of ActiveRecord::InsertAll::Builder, This method implements standard bulk inserts for all databases, but should be overridden by adapters to implement common features with non-standard syntax like handling duplicates or returning values.


578
579
580
581
582
583
584
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 578

def build_insert_sql(insert) # :nodoc:
  if insert.skip_duplicates? || insert.update_duplicates?
    raise NotImplementedError, "#{self.class} should define `build_insert_sql` to implement adapter-specific logic for handling duplicates during INSERT"
  end

  "INSERT #{insert.into} #{insert.values_list}"
end

#case_insensitive_comparison(attribute, value) ⇒ Object

:nodoc:


549
550
551
552
553
554
555
556
557
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 549

def case_insensitive_comparison(attribute, value) # :nodoc:
  column = column_for_attribute(attribute)

  if can_perform_case_insensitive_comparison_for?(column)
    attribute.lower.eq(attribute.relation.lower(value))
  else
    attribute.eq(value)
  end
end

#case_sensitive_comparison(attribute, value) ⇒ Object

:nodoc:


545
546
547
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 545

def case_sensitive_comparison(attribute, value) # :nodoc:
  attribute.eq(value)
end

#check_versionObject

:nodoc:


593
594
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 593

def check_version # :nodoc:
end

#clear_cache!Object

Clear any caching the database adapter may be doing.


514
515
516
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 514

def clear_cache!
  @lock.synchronize { @statements.clear } if @statements
end

#closeObject

Check the connection back in to the connection pool


565
566
567
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 565

def close
  pool.checkin self
end

#database_versionObject

:nodoc:


589
590
591
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 589

def database_version # :nodoc:
  schema_cache.database_version
end

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean)

569
570
571
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 569

def default_index_type?(index) # :nodoc:
  index.using.nil?
end

#default_uniqueness_comparison(attribute, value, klass) ⇒ Object

:nodoc:


541
542
543
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 541

def default_uniqueness_comparison(attribute, value, klass) # :nodoc:
  attribute.eq(value)
end

#disable_extension(name) ⇒ Object

This is meant to be implemented by the adapters that support extensions


422
423
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 422

def disable_extension(name)
end

#disable_referential_integrityObject

Override to turn off referential integrity while executing &block.


460
461
462
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 460

def disable_referential_integrity
  yield
end

#discard!Object

Immediately forget this connection ever existed. Unlike disconnect!, this will not communicate with the server.

After calling this method, the behavior of all other methods becomes undefined. This is called internally just before a forked process gets rid of a connection that belonged to its parent.


493
494
495
496
497
498
499
500
501
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 493

def discard!
  # This should be overridden by concrete adapters.
  #
  # Prevent @connection's finalizer from touching the socket, or
  # otherwise communicating with its server, when it is collected.
  if schema_cache.connection == self
    schema_cache.connection = nil
  end
end

#disconnect!Object

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


482
483
484
485
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 482

def disconnect!
  clear_cache!
  reset_transaction
end

#enable_extension(name) ⇒ Object

This is meant to be implemented by the adapters that support extensions


426
427
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 426

def enable_extension(name)
end

#expireObject

this method must only be called while holding connection pool's mutex


205
206
207
208
209
210
211
212
213
214
215
216
217
218
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 205

def expire
  if in_use?
    if @owner != Thread.current
      raise ActiveRecordError, "Cannot expire connection, " \
        "it is owned by a different thread: #{@owner}. " \
        "Current thread: #{Thread.current}."
    end

    @idle_since = Concurrent.monotonic_time
    @owner = nil
  else
    raise ActiveRecordError, "Cannot expire connection, it is not currently leased."
  end
end

#extensionsObject

A list of extensions, to be filled in by adapters that support them.


448
449
450
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 448

def extensions
  []
end

#get_advisory_lock(lock_id) ⇒ Object

This is meant to be implemented by the adapters that support advisory locks

Return true if we got the lock, otherwise false


437
438
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 437

def get_advisory_lock(lock_id) # :nodoc:
end

#get_database_versionObject

:nodoc:


586
587
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 586

def get_database_version # :nodoc:
end

#index_algorithmsObject

A list of index algorithms, to be filled by adapters that support them.


453
454
455
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 453

def index_algorithms
  {}
end

#leaseObject

this method must only be called while holding connection pool's mutex


180
181
182
183
184
185
186
187
188
189
190
191
192
193
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 180

def lease
  if in_use?
    msg = +"Cannot lease connection, "
    if @owner == Thread.current
      msg << "it is already leased by the current thread."
    else
      msg << "it is already in use by a different thread: #{@owner}. " \
             "Current thread: #{Thread.current}."
    end
    raise ActiveRecordError, msg
  end

  @owner = Thread.current
end

#migration_contextObject

:nodoc:


126
127
128
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 126

def migration_context # :nodoc:
  MigrationContext.new(migrations_paths, schema_migration)
end

#migrations_pathsObject

:nodoc:


122
123
124
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 122

def migrations_paths # :nodoc:
  @config[:migrations_paths] || Migrator.migrations_paths
end

#prefetch_primary_key?(table_name = nil) ⇒ Boolean

Should primary key values be selected from their corresponding sequence before the insert statement? If true, next_sequence_value is called before each insert to set the record's primary key.

Returns:

  • (Boolean)

280
281
282
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 280

def prefetch_primary_key?(table_name = nil)
  false
end

#prepared_statementsObject


148
149
150
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 148

def prepared_statements
  @prepared_statements && !prepared_statements_disabled_cache.include?(object_id)
end

#prepared_statements_disabled_cacheObject

:nodoc:


152
153
154
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 152

def prepared_statements_disabled_cache # :nodoc:
  Thread.current[:ar_prepared_statements_disabled_cache] ||= Set.new
end

#preventing_writes?Boolean

Determines whether writes are currently being prevents.

Returns true if the connection is a replica, or if prevent_writes is set to true.

Returns:

  • (Boolean)

118
119
120
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 118

def preventing_writes?
  replica? || ActiveRecord::Base.connection_handler.prevent_writes
end

#raw_connectionObject

Provides access to the underlying database driver for this adapter. For example, this method returns a Mysql2::Client object in case of Mysql2Adapter, and a PG::Connection object in case of PostgreSQLAdapter.

This is useful for when you need to call a proprietary method such as PostgreSQL's lo_* methods.


536
537
538
539
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 536

def raw_connection
  disable_lazy_transactions!
  @connection
end

#reconnect!Object

Disconnects from the database if already connected, and establishes a new connection with the database. Implementors should call super if they override the default implementation.


475
476
477
478
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 475

def reconnect!
  clear_cache!
  reset_transaction
end

#release_advisory_lock(lock_id) ⇒ Object

This is meant to be implemented by the adapters that support advisory locks.

Return true if we released the lock, otherwise false


444
445
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 444

def release_advisory_lock(lock_id) # :nodoc:
end

#replica?Boolean

Returns:

  • (Boolean)

106
107
108
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 106

def replica?
  @config[:replica] || false
end

#requires_reloading?Boolean

Returns true if its required to reload the connection between requests for development mode.

Returns:

  • (Boolean)

519
520
521
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 519

def requires_reloading?
  false
end

#reset!Object

Reset the state of this connection, directing the DBMS to clear transactions and other connection-related server-side state. Usually a database-dependent operation.

The default implementation does nothing; the implementation should be overridden by concrete adapters.


509
510
511
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 509

def reset!
  # this should be overridden by concrete adapters
end

#schema_cacheObject


195
196
197
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 195

def schema_cache
  @pool.get_schema_cache(self)
end

#schema_cache=(cache) ⇒ Object


199
200
201
202
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 199

def schema_cache=(cache)
  cache.connection = self
  @pool.set_schema_cache(cache)
end

#schema_migrationObject

:nodoc:


130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 130

def schema_migration # :nodoc:
  @schema_migration ||= begin
                          conn = self
                          spec_name = conn.pool.pool_config.connection_specification_name

                          return ActiveRecord::SchemaMigration if spec_name == "ActiveRecord::Base"

                          schema_migration_name = "#{spec_name}::SchemaMigration"

                          Class.new(ActiveRecord::SchemaMigration) do
                            define_singleton_method(:name) { schema_migration_name }
                            define_singleton_method(:to_s) { schema_migration_name }

                            self.connection_specification_name = spec_name
                          end
                        end
end

#seconds_idleObject

Seconds since this connection was returned to the pool


234
235
236
237
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 234

def seconds_idle # :nodoc:
  return 0 if in_use?
  Concurrent.monotonic_time - @idle_since
end

#steal!Object

this method must only be called while holding connection pool's mutex (and a desire for segfaults)


221
222
223
224
225
226
227
228
229
230
231
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 221

def steal! # :nodoc:
  if in_use?
    if @owner != Thread.current
      pool.send :remove_connection_from_thread_cache, self, @owner

      @owner = Thread.current
    end
  else
    raise ActiveRecordError, "Cannot steal connection, it is not currently leased."
  end
end

#supports_advisory_locks?Boolean

Does this adapter support application-enforced advisory locking?

Returns:

  • (Boolean)

273
274
275
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 273

def supports_advisory_locks?
  false
end

#supports_bulk_alter?Boolean

Returns:

  • (Boolean)

263
264
265
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 263

def supports_bulk_alter?
  false
end

#supports_check_constraints?Boolean

Does this adapter support creating check constraints?

Returns:

  • (Boolean)

342
343
344
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 342

def supports_check_constraints?
  false
end

#supports_comments?Boolean

Does this adapter support metadata comments on database objects (tables, columns, indexes)?

Returns:

  • (Boolean)

367
368
369
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 367

def supports_comments?
  false
end

#supports_comments_in_create?Boolean

Can comments for tables, columns, and indexes be specified in create/alter table statements?

Returns:

  • (Boolean)

372
373
374
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 372

def supports_comments_in_create?
  false
end

#supports_common_table_expressions?Boolean

Returns:

  • (Boolean)

397
398
399
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 397

def supports_common_table_expressions?
  false
end

#supports_datetime_with_precision?Boolean

Does this adapter support datetime with precision?

Returns:

  • (Boolean)

357
358
359
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 357

def supports_datetime_with_precision?
  false
end

#supports_ddl_transactions?Boolean

Does this adapter support DDL rollbacks in transactions? That is, would CREATE TABLE or ALTER TABLE get rolled back by a transaction?

Returns:

  • (Boolean)

259
260
261
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 259

def supports_ddl_transactions?
  false
end

#supports_explain?Boolean

Does this adapter support explain?

Returns:

  • (Boolean)

304
305
306
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 304

def supports_explain?
  false
end

#supports_expression_index?Boolean

Does this adapter support expression indices?

Returns:

  • (Boolean)

299
300
301
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 299

def supports_expression_index?
  false
end

#supports_extensions?Boolean

Does this adapter support database extensions?

Returns:

  • (Boolean)

314
315
316
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 314

def supports_extensions?
  false
end

#supports_foreign_keys?Boolean

Does this adapter support creating foreign key constraints?

Returns:

  • (Boolean)

325
326
327
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 325

def supports_foreign_keys?
  false
end

#supports_foreign_keys_in_create?Boolean

Does this adapter support creating foreign key constraints in the same statement as creating the table?

Returns:

  • (Boolean)

336
337
338
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 336

def supports_foreign_keys_in_create?
  supports_foreign_keys?
end

#supports_foreign_tables?Boolean

Does this adapter support foreign/external tables?

Returns:

  • (Boolean)

388
389
390
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 388

def supports_foreign_tables?
  false
end

#supports_index_sort_order?Boolean

Does this adapter support index sort order?

Returns:

  • (Boolean)

289
290
291
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 289

def supports_index_sort_order?
  false
end

#supports_indexes_in_create?Boolean

Does this adapter support creating indexes in the same statement as creating the table?

Returns:

  • (Boolean)

320
321
322
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 320

def supports_indexes_in_create?
  false
end

#supports_insert_conflict_target?Boolean

Returns:

  • (Boolean)

417
418
419
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 417

def supports_insert_conflict_target?
  false
end

#supports_insert_on_duplicate_skip?Boolean

Returns:

  • (Boolean)

409
410
411
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 409

def supports_insert_on_duplicate_skip?
  false
end

#supports_insert_on_duplicate_update?Boolean

Returns:

  • (Boolean)

413
414
415
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 413

def supports_insert_on_duplicate_update?
  false
end

#supports_insert_returning?Boolean

Returns:

  • (Boolean)

405
406
407
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 405

def supports_insert_returning?
  false
end

#supports_json?Boolean

Does this adapter support json data type?

Returns:

  • (Boolean)

362
363
364
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 362

def supports_json?
  false
end

#supports_lazy_transactions?Boolean

Returns:

  • (Boolean)

401
402
403
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 401

def supports_lazy_transactions?
  false
end

#supports_materialized_views?Boolean

Does this adapter support materialized views?

Returns:

  • (Boolean)

352
353
354
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 352

def supports_materialized_views?
  false
end

#supports_multi_insert?Boolean

Does this adapter support multi-value insert?

Returns:

  • (Boolean)

377
378
379
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 377

def supports_multi_insert?
  true
end

#supports_optimizer_hints?Boolean

Does this adapter support optimizer hints?

Returns:

  • (Boolean)

393
394
395
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 393

def supports_optimizer_hints?
  false
end

#supports_partial_index?Boolean

Does this adapter support partial indices?

Returns:

  • (Boolean)

294
295
296
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 294

def supports_partial_index?
  false
end

#supports_partitioned_indexes?Boolean

Returns:

  • (Boolean)

284
285
286
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 284

def supports_partitioned_indexes?
  false
end

#supports_savepoints?Boolean

Does this adapter support savepoints?

Returns:

  • (Boolean)

268
269
270
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 268

def supports_savepoints?
  false
end

#supports_transaction_isolation?Boolean

Does this adapter support setting the isolation level for a transaction?

Returns:

  • (Boolean)

309
310
311
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 309

def supports_transaction_isolation?
  false
end

#supports_validate_constraints?Boolean

Does this adapter support creating invalid constraints?

Returns:

  • (Boolean)

330
331
332
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 330

def supports_validate_constraints?
  false
end

#supports_views?Boolean

Does this adapter support views?

Returns:

  • (Boolean)

347
348
349
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 347

def supports_views?
  false
end

#supports_virtual_columns?Boolean

Does this adapter support virtual columns?

Returns:

  • (Boolean)

383
384
385
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 383

def supports_virtual_columns?
  false
end

#unprepared_statementObject


239
240
241
242
243
244
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 239

def unprepared_statement
  cache = prepared_statements_disabled_cache.add(object_id) if @prepared_statements
  yield
ensure
  cache&.delete(object_id)
end

#use_metadata_table?Boolean

Returns:

  • (Boolean)

110
111
112
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 110

def 
  @config.fetch(:use_metadata_table, true)
end

#valid_type?(type) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean)

175
176
177
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 175

def valid_type?(type) # :nodoc:
  !native_database_types[type].nil?
end

#verify!Object

Checks whether the connection to the database is still active (i.e. not stale). This is done under the hood by calling #active?. If the connection is no longer active, then this method will reconnect to the database.


526
527
528
# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 526

def verify!
  reconnect! unless active?
end