Class: ActiveRecord::ConnectionAdapters::AbstractAdapter

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

Constant Summary collapse

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

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, #type_cast_from_column, #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, #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?, #transaction_state, #truncate, #truncate_tables, #update, #with_yaml_fallback, #write_query?

Methods included from SchemaStatements

#add_column, #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, #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_exists?, #index_name, #index_name_exists?, #indexes, #internal_string_options_for_primary_key, #native_database_types, #options_include_default?, #primary_key, #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

Constructor Details

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

:nodoc:



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

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

  if self.class.type_cast_config_to_boolean(config.fetch(:prepared_statements) { true })
    @prepared_statements = true
    @visitor.extend(DetermineIfPreparableVisitor)
  else
    @prepared_statements = false
  end

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

Instance Attribute Details

#lock ⇒ Object (readonly)

Returns the value of attribute lock.



83
84
85
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 83

def lock
  @lock
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



83
84
85
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 83

def logger
  @logger
end

#owner ⇒ Object (readonly) Also known as: in_use?

Returns the value of attribute owner.



83
84
85
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 83

def owner
  @owner
end

#pool ⇒ Object

Returns the value of attribute pool.



82
83
84
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 82

def pool
  @pool
end

#visitor ⇒ Object (readonly)

Returns the value of attribute visitor.



83
84
85
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 83

def visitor
  @visitor
end

Class Method Details

.build_read_query_regexp(*parts) ⇒ Object

:nodoc:



109
110
111
112
113
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 109

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) 


291
292
293
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 291

def self.database_exists?(config)
  raise NotImplementedError
end

.quoted_column_names ⇒ Object

:nodoc:



115
116
117
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 115

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

.quoted_table_names ⇒ Object

:nodoc:



119
120
121
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 119

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

.type_cast_config_to_boolean(config) ⇒ Object 



98
99
100
101
102
103
104
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 98

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

.type_cast_config_to_integer(config) ⇒ Object 



88
89
90
91
92
93
94
95
96
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 88

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) 


502
503
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 502

def active?
end

#adapter_name ⇒ Object

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



286
287
288
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 286

def adapter_name
  self.class::ADAPTER_NAME
end

#advisory_locks_enabled? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


462
463
464
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 462

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.



615
616
617
618
619
620
621
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 615

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:



582
583
584
585
586
587
588
589
590
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 582

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:



578
579
580
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 578

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

#check_version ⇒ Object

:nodoc:



630
631
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 630

def check_version # :nodoc:
end

#clear_cache! ⇒ Object

Clear any caching the database adapter may be doing.



547
548
549
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 547

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

#close ⇒ Object

Check the connection back in to the connection pool



598
599
600
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 598

def close
  pool.checkin self
end

#column_name_for_operation(operation, node) ⇒ Object

:nodoc:



602
603
604
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 602

def column_name_for_operation(operation, node) # :nodoc:
  visitor.compile(node)
end

#database_version ⇒ Object

:nodoc:



626
627
628
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 626

def database_version # :nodoc:
  schema_cache.database_version
end

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


606
607
608
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 606

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

#default_uniqueness_comparison(attribute, value, klass) ⇒ Object

:nodoc:



574
575
576
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 574

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



455
456
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 455

def disable_extension(name)
end

#disable_referential_integrity ⇒ Object

Override to turn off referential integrity while executing &block.



493
494
495
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 493

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.



526
527
528
529
530
531
532
533
534
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 526

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.



515
516
517
518
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 515

def disconnect!
  clear_cache!
  reset_transaction
end

#enable_extension(name) ⇒ Object

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



459
460
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 459

def enable_extension(name)
end

#expire ⇒ Object

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



243
244
245
246
247
248
249
250
251
252
253
254
255
256
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 243

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

#extensions ⇒ Object

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



481
482
483
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 481

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



470
471
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 470

def get_advisory_lock(lock_id) # :nodoc:
end

#get_database_version ⇒ Object

:nodoc:



623
624
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 623

def get_database_version # :nodoc:
end

#index_algorithms ⇒ Object

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



486
487
488
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 486

def index_algorithms
  {}
end

#lease ⇒ Object

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



218
219
220
221
222
223
224
225
226
227
228
229
230
231
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 218

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_context ⇒ Object

:nodoc:



165
166
167
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 165

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

#migrations_paths ⇒ Object

:nodoc:



161
162
163
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 161

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) 


318
319
320
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 318

def prefetch_primary_key?(table_name = nil)
  false
end

#prepared_statements ⇒ Object 



186
187
188
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 186

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

#prepared_statements_disabled_cache ⇒ Object

:nodoc:



190
191
192
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 190

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) 


157
158
159
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 157

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

#raw_connection ⇒ Object

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.



569
570
571
572
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 569

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.



508
509
510
511
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 508

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



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

def release_advisory_lock(lock_id) # :nodoc:
end

#replica? ⇒ Boolean

Returns:

  • (Boolean) 


149
150
151
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 149

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) 


552
553
554
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 552

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.



542
543
544
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 542

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

#schema_cache ⇒ Object 



233
234
235
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 233

def schema_cache
  @pool.get_schema_cache(self)
end

#schema_cache=(cache) ⇒ Object 



237
238
239
240
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 237

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

#schema_migration ⇒ Object

:nodoc:



169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 169

def schema_migration # :nodoc:
  @schema_migration ||= begin
                          conn = self
                          spec_name = conn.pool.spec.name
                          name = "#{spec_name}::SchemaMigration"

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

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

                            self.connection_specification_name = spec_name
                          end
                        end
end

#seconds_idle ⇒ Object

Seconds since this connection was returned to the pool



272
273
274
275
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 272

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)



259
260
261
262
263
264
265
266
267
268
269
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 259

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) 


311
312
313
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 311

def supports_advisory_locks?
  false
end

#supports_bulk_alter? ⇒ Boolean

Returns:

  • (Boolean) 


301
302
303
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 301

def supports_bulk_alter?
  false
end

#supports_comments? ⇒ Boolean

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

Returns:

  • (Boolean) 


400
401
402
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 400

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) 


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

def supports_comments_in_create?
  false
end

#supports_common_table_expressions? ⇒ Boolean

Returns:

  • (Boolean) 


430
431
432
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 430

def supports_common_table_expressions?
  false
end

#supports_datetime_with_precision? ⇒ Boolean

Does this adapter support datetime with precision?

Returns:

  • (Boolean) 


390
391
392
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 390

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) 


297
298
299
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 297

def supports_ddl_transactions?
  false
end

#supports_explain? ⇒ Boolean

Does this adapter support explain?

Returns:

  • (Boolean) 


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

def supports_explain?
  false
end

#supports_expression_index? ⇒ Boolean

Does this adapter support expression indices?

Returns:

  • (Boolean) 


337
338
339
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 337

def supports_expression_index?
  false
end

#supports_extensions? ⇒ Boolean

Does this adapter support database extensions?

Returns:

  • (Boolean) 


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

def supports_extensions?
  false
end

#supports_foreign_keys? ⇒ Boolean

Does this adapter support creating foreign key constraints?

Returns:

  • (Boolean) 


363
364
365
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 363

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) 


374
375
376
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 374

def supports_foreign_keys_in_create?
  supports_foreign_keys?
end

#supports_foreign_tables? ⇒ Boolean

Does this adapter support foreign/external tables?

Returns:

  • (Boolean) 


421
422
423
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 421

def supports_foreign_tables?
  false
end

#supports_index_sort_order? ⇒ Boolean

Does this adapter support index sort order?

Returns:

  • (Boolean) 


327
328
329
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 327

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) 


358
359
360
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 358

def supports_indexes_in_create?
  false
end

#supports_insert_conflict_target? ⇒ Boolean

Returns:

  • (Boolean) 


450
451
452
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 450

def supports_insert_conflict_target?
  false
end

#supports_insert_on_duplicate_skip? ⇒ Boolean

Returns:

  • (Boolean) 


442
443
444
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 442

def supports_insert_on_duplicate_skip?
  false
end

#supports_insert_on_duplicate_update? ⇒ Boolean

Returns:

  • (Boolean) 


446
447
448
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 446

def supports_insert_on_duplicate_update?
  false
end

#supports_insert_returning? ⇒ Boolean

Returns:

  • (Boolean) 


438
439
440
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 438

def supports_insert_returning?
  false
end

#supports_json? ⇒ Boolean

Does this adapter support json data type?

Returns:

  • (Boolean) 


395
396
397
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 395

def supports_json?
  false
end

#supports_lazy_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


434
435
436
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 434

def supports_lazy_transactions?
  false
end

#supports_materialized_views? ⇒ Boolean

Does this adapter support materialized views?

Returns:

  • (Boolean) 


385
386
387
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 385

def supports_materialized_views?
  false
end

#supports_multi_insert? ⇒ Boolean

Does this adapter support multi-value insert?

Returns:

  • (Boolean) 


410
411
412
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 410

def supports_multi_insert?
  true
end

#supports_optimizer_hints? ⇒ Boolean

Does this adapter support optimizer hints?

Returns:

  • (Boolean) 


426
427
428
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 426

def supports_optimizer_hints?
  false
end

#supports_partial_index? ⇒ Boolean

Does this adapter support partial indices?

Returns:

  • (Boolean) 


332
333
334
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 332

def supports_partial_index?
  false
end

#supports_partitioned_indexes? ⇒ Boolean

Returns:

  • (Boolean) 


322
323
324
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 322

def supports_partitioned_indexes?
  false
end

#supports_savepoints? ⇒ Boolean

Does this adapter support savepoints?

Returns:

  • (Boolean) 


306
307
308
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 306

def supports_savepoints?
  false
end

#supports_transaction_isolation? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

def supports_transaction_isolation?
  false
end

#supports_validate_constraints? ⇒ Boolean

Does this adapter support creating invalid constraints?

Returns:

  • (Boolean) 


368
369
370
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 368

def supports_validate_constraints?
  false
end

#supports_views? ⇒ Boolean

Does this adapter support views?

Returns:

  • (Boolean) 


380
381
382
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 380

def supports_views?
  false
end

#supports_virtual_columns? ⇒ Boolean

Does this adapter support virtual columns?

Returns:

  • (Boolean) 


416
417
418
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 416

def supports_virtual_columns?
  false
end

#unprepared_statement ⇒ Object 



277
278
279
280
281
282
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 277

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

#valid_type?(type) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


213
214
215
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 213

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.



559
560
561
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 559

def verify!
  reconnect! unless active?
end