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

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{(?:\-\-.*\n)*|/\*(?:[^\*]|\*[^/])*\*/}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, #in_clause_length, #index_name_length, #max_identifier_length, #table_alias_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, #explain, #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

Constructor Details

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

:nodoc:



82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 82

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

#lock ⇒ Object (readonly)

Returns the value of attribute lock.



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

def lock
  @lock
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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

def logger
  @logger
end

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

Returns the value of attribute owner.



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

def owner
  @owner
end

#pool ⇒ Object

Returns the value of attribute pool.



41
42
43
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 41

def pool
  @pool
end

#visitor ⇒ Object (readonly)

Returns the value of attribute visitor.



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

def visitor
  @visitor
end

Class Method Details

.build_read_query_regexp(*parts) ⇒ Object

:nodoc:



68
69
70
71
72
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 68

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) 


266
267
268
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 266

def self.database_exists?(config)
  raise NotImplementedError
end

.quoted_column_names ⇒ Object

:nodoc:



74
75
76
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 74

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

.quoted_table_names ⇒ Object

:nodoc:



78
79
80
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 78

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

.type_cast_config_to_boolean(config) ⇒ Object 



57
58
59
60
61
62
63
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 57

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

.type_cast_config_to_integer(config) ⇒ Object 



47
48
49
50
51
52
53
54
55
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 47

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 'lib/active_record/connection_adapters/abstract_adapter.rb', line 469

def active?
end

#adapter_name ⇒ Object

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



261
262
263
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 261

def adapter_name
  self.class::ADAPTER_NAME
end

#advisory_locks_enabled? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


429
430
431
 
# File '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.



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

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:



555
556
557
558
559
560
561
562
563
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 555

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:



551
552
553
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 551

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

#check_version ⇒ Object

:nodoc:



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

def check_version # :nodoc:
end

#clear_cache! ⇒ Object

Clear any caching the database adapter may be doing.



520
521
522
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 520

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

#close ⇒ Object

Check the connection back in to the connection pool



571
572
573
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 571

def close
  pool.checkin self
end

#connection_klass ⇒ Object

:nodoc:



204
205
206
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 204

def connection_klass # :nodoc:
  @pool.connection_klass
end

#database_version ⇒ Object

:nodoc:



595
596
597
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 595

def database_version # :nodoc:
  schema_cache.database_version
end

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


575
576
577
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 575

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

#default_uniqueness_comparison(attribute, value) ⇒ Object

:nodoc:



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

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

#disable_extension(name) ⇒ Object

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



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

def disable_extension(name)
end

#disable_referential_integrity ⇒ Object

Override to turn off referential integrity while executing &block.



460
461
462
 
# File '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 '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 '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 'lib/active_record/connection_adapters/abstract_adapter.rb', line 426

def enable_extension(name)
end

#expire ⇒ 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 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.



448
449
450
 
# File '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 'lib/active_record/connection_adapters/abstract_adapter.rb', line 437

def get_advisory_lock(lock_id) # :nodoc:
end

#get_database_version ⇒ Object

:nodoc:



592
593
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 592

def get_database_version # :nodoc:
end

#index_algorithms ⇒ Object

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



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

def index_algorithms
  {}
end

#lease ⇒ Object

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



189
190
191
192
193
194
195
196
197
198
199
200
201
202
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 189

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:



134
135
136
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 134

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

#migrations_paths ⇒ Object

:nodoc:



130
131
132
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 130

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) 


293
294
295
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 293

def prefetch_primary_key?(table_name = nil)
  false
end

#prepared_statements? ⇒ Boolean Also known as: prepared_statements

Returns:

  • (Boolean) 


156
157
158
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 156

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

#prepared_statements_disabled_cache ⇒ Object

:nodoc:



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

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 prevented.

Returns true if the connection is a replica.

If the application is using legacy handling, returns true if connection_handler.prevent_writes is set.

If the application is using the new connection handling will return true based on current_preventing_writes.

Returns:

  • (Boolean) 


122
123
124
125
126
127
128
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 122

def preventing_writes?
  return true if replica?
  return ActiveRecord::Base.connection_handler.prevent_writes if ActiveRecord::Base.legacy_connection_handling
  return false if connection_klass.nil?

  connection_klass.current_preventing_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.



542
543
544
545
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 542

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 '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 'lib/active_record/connection_adapters/abstract_adapter.rb', line 444

def release_advisory_lock(lock_id) # :nodoc:
end

#replica? ⇒ Boolean

Returns:

  • (Boolean) 


105
106
107
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 105

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) 


525
526
527
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 525

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 'lib/active_record/connection_adapters/abstract_adapter.rb', line 509

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

#schema_cache ⇒ Object 



208
209
210
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 208

def schema_cache
  @pool.get_schema_cache(self)
end

#schema_cache=(cache) ⇒ Object 



212
213
214
215
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 212

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

#schema_migration ⇒ Object

:nodoc:



138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 138

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_idle ⇒ Object

Seconds since this connection was returned to the pool



247
248
249
250
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 247

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)



234
235
236
237
238
239
240
241
242
243
244
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 234

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) 


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

def supports_advisory_locks?
  false
end

#supports_bulk_alter? ⇒ Boolean

Returns:

  • (Boolean) 


276
277
278
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 276

def supports_bulk_alter?
  false
end

#supports_check_constraints? ⇒ Boolean

Does this adapter support creating check constraints?

Returns:

  • (Boolean) 


348
349
350
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 348

def supports_check_constraints?
  false
end

#supports_comments? ⇒ Boolean

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

Returns:

  • (Boolean) 


373
374
375
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 373

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) 


378
379
380
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 378

def supports_comments_in_create?
  false
end

#supports_common_table_expressions? ⇒ Boolean

Returns:

  • (Boolean) 


397
398
399
 
# File '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) 


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

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) 


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

def supports_ddl_transactions?
  false
end

#supports_explain? ⇒ Boolean

Does this adapter support explain?

Returns:

  • (Boolean) 


317
318
319
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 317

def supports_explain?
  false
end

#supports_expression_index? ⇒ Boolean

Does this adapter support expression indices?

Returns:

  • (Boolean) 


312
313
314
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 312

def supports_expression_index?
  false
end

#supports_extensions? ⇒ Boolean

Does this adapter support database extensions?

Returns:

  • (Boolean) 


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

def supports_extensions?
  false
end

#supports_foreign_keys? ⇒ Boolean

Does this adapter support creating foreign key constraints?

Returns:

  • (Boolean) 


338
339
340
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 338

def supports_foreign_keys?
  false
end

#supports_foreign_tables? ⇒ Boolean

Does this adapter support foreign/external tables?

Returns:

  • (Boolean) 


388
389
390
 
# File '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) 


302
303
304
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 302

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) 


333
334
335
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 333

def supports_indexes_in_create?
  false
end

#supports_insert_conflict_target? ⇒ Boolean

Returns:

  • (Boolean) 


417
418
419
 
# File '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 '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 '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 '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) 


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

def supports_json?
  false
end

#supports_lazy_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


401
402
403
 
# File '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) 


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

def supports_materialized_views?
  false
end

#supports_optimizer_hints? ⇒ Boolean

Does this adapter support optimizer hints?

Returns:

  • (Boolean) 


393
394
395
 
# File '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) 


307
308
309
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 307

def supports_partial_index?
  false
end

#supports_partitioned_indexes? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_partitioned_indexes?
  false
end

#supports_savepoints? ⇒ Boolean

Does this adapter support savepoints?

Returns:

  • (Boolean) 


281
282
283
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 281

def supports_savepoints?
  false
end

#supports_transaction_isolation? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

def supports_transaction_isolation?
  false
end

#supports_validate_constraints? ⇒ Boolean

Does this adapter support creating invalid constraints?

Returns:

  • (Boolean) 


343
344
345
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 343

def supports_validate_constraints?
  false
end

#supports_views? ⇒ Boolean

Does this adapter support views?

Returns:

  • (Boolean) 


353
354
355
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 353

def supports_views?
  false
end

#supports_virtual_columns? ⇒ Boolean

Does this adapter support virtual columns?

Returns:

  • (Boolean) 


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

def supports_virtual_columns?
  false
end

#throw_away! ⇒ Object

Removes the connection from the pool and disconnect it.



514
515
516
517
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 514

def throw_away!
  pool.remove self
  disconnect!
end

#unprepared_statement ⇒ Object 



252
253
254
255
256
257
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 252

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) 


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

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

#valid_type?(type) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


184
185
186
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 184

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.



532
533
534
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 532

def verify!
  reconnect! unless active?
end