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 Abstract Adapter

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)|/\*(?:[^*]|\*[^/])*\*/}
TYPE_MAP = 
Type::TypeMap.new.tap { |m| initialize_type_map(m) }
EXTENDED_TYPE_MAPS = 
Concurrent::Map.new

Constants included from QueryCache

QueryCache::DEFAULT_SIZE

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

#index_name_length, #max_identifier_length, #table_alias_length, #table_name_length

Methods included from Quoting

#cast_bound_value, #column_name_matcher, #column_name_with_order_matcher, #lookup_cast_type_from_column, #quote, #quote_bound_value, #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_restart_db_transaction, #exec_rollback_db_transaction, #exec_update, #execute, #explain, #high_precision_current_timestamp, #insert, #insert_fixture, #insert_fixtures_set, #internal_exec_query, #mark_transaction_written_if_write, #query, #query_value, #query_values, #reset_sequence!, #reset_transaction, #restart_db_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, #build_add_column_definition, #build_change_column_default_definition, #build_create_index_definition, #build_create_join_table_definition, #build_create_table_definition, #bulk_change_table, #change_column, #change_column_comment, #change_column_default, #change_column_null, #change_table, #change_table_comment, #check_constraint_exists?, #check_constraint_options, #check_constraints, #column_exists?, #columns, #columns_for_distinct, #create_join_table, #create_schema_dumper, #create_table, #data_source_exists?, #data_sources, #distinct_relation_for_primary_key, #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, #max_index_name_size, #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, #schema_creation, #table_alias_for, #table_comment, #table_exists?, #table_options, #tables, #type_to_sql, #update_table_definition, #use_foreign_keys?, #valid_column_definition_options, #valid_primary_key_options, #valid_table_definition_options, #view_exists?, #views

Constructor Details

#initialize(config_or_deprecated_connection, deprecated_logger = nil, deprecated_connection_options = nil, deprecated_config = nil) ⇒ AbstractAdapter

:nodoc:



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

def initialize(config_or_deprecated_connection, deprecated_logger = nil, deprecated_connection_options = nil, deprecated_config = nil) # :nodoc:
  super()

  @raw_connection = nil
  @unconfigured_connection = nil

  if config_or_deprecated_connection.is_a?(Hash)
    @config = config_or_deprecated_connection.symbolize_keys
    @logger = ActiveRecord::Base.logger

    if deprecated_logger || deprecated_connection_options || deprecated_config
      raise ArgumentError, "when initializing an ActiveRecord adapter with a config hash, that should be the only argument"
    end
  else
    # Soft-deprecated for now; we'll probably warn in future.

    @unconfigured_connection = config_or_deprecated_connection
    @logger = deprecated_logger || ActiveRecord::Base.logger
    if deprecated_config
      @config = (deprecated_config || {}).symbolize_keys
      @connection_parameters = deprecated_connection_options
    else
      @config = (deprecated_connection_options || {}).symbolize_keys
      @connection_parameters = nil
    end
  end

  @owner = nil
  @instrumenter = ActiveSupport::Notifications.instrumenter
  @pool = ActiveRecord::ConnectionAdapters::NullPool.new
  @idle_since = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  @visitor = arel_visitor
  @statements = build_statement_pool
  self.lock_thread = nil

  @prepared_statements = !ActiveRecord.disable_prepared_statements && self.class.type_cast_config_to_boolean(
    @config.fetch(:prepared_statements) { default_prepared_statements }
  )

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

  @default_timezone = self.class.validate_default_timezone(@config[:default_timezone])

  @raw_connection_dirty = false
  @verified = false
end

Instance Attribute Details

#lock ⇒ Object (readonly)

Returns the value of attribute lock.



45
46
47
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 45

def lock
  @lock
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



45
46
47
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 45

def logger
  @logger
end

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

Returns the value of attribute owner.



45
46
47
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 45

def owner
  @owner
end

#pool ⇒ Object

Returns the value of attribute pool.



44
45
46
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 44

def pool
  @pool
end

#visitor ⇒ Object (readonly)

Returns the value of attribute visitor.



45
46
47
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 45

def visitor
  @visitor
end

Class Method Details

.build_read_query_regexp(*parts) ⇒ Object

:nodoc:



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

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) 


382
383
384
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 382

def self.database_exists?(config)
  new(config).database_exists?
end

.dbconsole(config, options = {}) ⇒ Object

Opens a database console session.

Raises:

  • (NotImplementedError) 


124
125
126
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 124

def self.dbconsole(config, options = {})
  raise NotImplementedError
end

.extended_type_map(default_timezone:) ⇒ Object

:nodoc:



892
893
894
895
896
897
898
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 892

def extended_type_map(default_timezone:) # :nodoc:
  Type::TypeMap.new(self::TYPE_MAP).tap do |m|
    register_class_with_precision m, %r(\A[^\(]*time)i, Type::Time, timezone: default_timezone
    register_class_with_precision m, %r(\A[^\(]*datetime)i, Type::DateTime, timezone: default_timezone
    m.alias_type %r(\A[^\(]*timestamp)i, "datetime"
  end
end

.find_cmd_and_exec(commands, *args) ⇒ Object

:doc:



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
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 95

def self.find_cmd_and_exec(commands, *args) # :doc:
  commands = Array(commands)

  dirs_on_path = ENV["PATH"].to_s.split(File::PATH_SEPARATOR)
  unless (ext = RbConfig::CONFIG["EXEEXT"]).empty?
    commands = commands.map { |cmd| "#{cmd}#{ext}" }
  end

  full_path_command = nil
  found = commands.detect do |cmd|
    dirs_on_path.detect do |path|
      full_path_command = File.join(path, cmd)
      begin
        stat = File.stat(full_path_command)
      rescue SystemCallError
      else
        stat.file? && stat.executable?
      end
    end
  end

  if found
    exec full_path_command, *args
  else
    abort("Couldn't find database client: #{commands.join(', ')}. Check your $PATH and try again.")
  end
end

.register_class_with_precision(mapping, key, klass, **kwargs) ⇒ Object

:nodoc:



885
886
887
888
889
890
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 885

def register_class_with_precision(mapping, key, klass, **kwargs) # :nodoc:
  mapping.register_type(key) do |*args|
    precision = extract_precision(args.last)
    klass.new(precision: precision, **kwargs)
  end
end

.type_cast_config_to_boolean(config) ⇒ Object 



68
69
70
71
72
73
74
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 68

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

.type_cast_config_to_integer(config) ⇒ Object 



58
59
60
61
62
63
64
65
66
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 58

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

.validate_default_timezone(config) ⇒ Object 



76
77
78
79
80
81
82
83
84
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 76

def self.validate_default_timezone(config)
  case config
  when nil
  when "utc", "local"
    config.to_sym
  else
    raise ArgumentError, "default_timezone must be either 'utc' or 'local'"
  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) 


674
675
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 674

def active?
end

#adapter_name ⇒ Object

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



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

def adapter_name
  self.class::ADAPTER_NAME
end

#add_enum_value ⇒ Object

This is meant to be implemented by the adapters that support custom enum types



612
613
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 612

def add_enum_value(*) # :nodoc:
end

#advisory_locks_enabled? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


619
620
621
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 619

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

#all_foreign_keys_valid? ⇒ Boolean

Override to check all foreign key constraints in a database.

Returns:

  • (Boolean) 


655
656
657
658
659
660
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 655

def all_foreign_keys_valid?
  check_all_foreign_keys_valid!
  true
rescue ActiveRecord::StatementInvalid
  false
end

#async_enabled? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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

def async_enabled? # :nodoc:
  supports_concurrent_connections? &&
    !ActiveRecord.async_query_executor.nil? && !pool.async_executor.nil?
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.



858
859
860
861
862
863
864
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 858

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:



829
830
831
832
833
834
835
836
837
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 829

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:



825
826
827
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 825

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

#check_all_foreign_keys_valid! ⇒ Object

Override to check all foreign key constraints in a database. The adapter should raise a ActiveRecord::StatementInvalid if foreign key constraints are not met.



666
667
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 666

def check_all_foreign_keys_valid!
end

#check_if_write_query(sql) ⇒ Object

:nodoc:



208
209
210
211
212
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 208

def check_if_write_query(sql) # :nodoc:
  if preventing_writes? && write_query?(sql)
    raise ActiveRecord::ReadOnlyError, "Write query attempted while in readonly mode: #{sql}"
  end
end

#check_version ⇒ Object

:nodoc:



873
874
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 873

def check_version # :nodoc:
end

#clean! ⇒ Object

:nodoc:



798
799
800
801
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 798

def clean! # :nodoc:
  @raw_connection_dirty = false
  @verified = nil
end

#clear_cache!(new_connection: false) ⇒ Object

Clear any caching the database adapter may be doing.



755
756
757
758
759
760
761
762
763
764
765
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 755

def clear_cache!(new_connection: false)
  if @statements
    @lock.synchronize do
      if new_connection
        @statements.reset
      else
        @statements.clear
      end
    end
  end
end

#close ⇒ Object

Check the connection back in to the connection pool



845
846
847
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 845

def close
  pool.checkin self
end

#connect! ⇒ Object 



793
794
795
796
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 793

def connect!
  verify!
  self
end

#connection_class ⇒ Object

:nodoc:



313
314
315
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 313

def connection_class # :nodoc:
  @pool.connection_class
end

#connection_retries ⇒ Object 



222
223
224
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 222

def connection_retries
  (@config[:connection_retries] || 1).to_i
end

#create_enum ⇒ Object

This is meant to be implemented by the adapters that support custom enum types



600
601
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 600

def create_enum(*) # :nodoc:
end

#database_exists? ⇒ Boolean

Returns:

  • (Boolean) 


386
387
388
389
390
391
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 386

def database_exists?
  connect!
  true
rescue ActiveRecord::NoDatabaseError
  false
end

#database_version ⇒ Object

:nodoc:



869
870
871
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 869

def database_version # :nodoc:
  schema_cache.database_version
end

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


849
850
851
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 849

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

#default_timezone ⇒ Object 



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

def default_timezone
  @default_timezone || ActiveRecord.default_timezone
end

#default_uniqueness_comparison(attribute, value) ⇒ Object

:nodoc:



821
822
823
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 821

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



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

def disable_extension(name, **)
end

#disable_referential_integrity ⇒ Object

Override to turn off referential integrity while executing &block.



650
651
652
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 650

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.



730
731
732
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 730

def discard!
  # This should be overridden by concrete adapters.
end

#disconnect! ⇒ Object

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



716
717
718
719
720
721
722
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 716

def disconnect!
  @lock.synchronize do
    clear_cache!(new_connection: true)
    reset_transaction
    @raw_connection_dirty = false
  end
end

#drop_enum ⇒ Object

This is meant to be implemented by the adapters that support custom enum types



604
605
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 604

def drop_enum(*) # :nodoc:
end

#enable_extension(name) ⇒ Object

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



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

def enable_extension(name, **)
end

#expire ⇒ Object

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



334
335
336
337
338
339
340
341
342
343
344
345
346
347
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 334

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

    @idle_since = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    @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.



638
639
640
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 638

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



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

def get_advisory_lock(lock_id) # :nodoc:
end

#get_database_version ⇒ Object

:nodoc:



866
867
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 866

def get_database_version # :nodoc:
end

#index_algorithms ⇒ Object

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



643
644
645
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 643

def index_algorithms
  {}
end

#internal_metadata ⇒ Object

:nodoc:



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

def internal_metadata # :nodoc:
  InternalMetadata.new(self)
end

#lease ⇒ Object

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



298
299
300
301
302
303
304
305
306
307
308
309
310
311
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 298

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

  @owner = ActiveSupport::IsolatedExecutionState.context
end

#lock_thread=(lock_thread) ⇒ Object

:nodoc:



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

def lock_thread=(lock_thread) # :nodoc:
  @lock =
  case lock_thread
  when Thread
    THREAD_LOCK
  when Fiber
    FIBER_LOCK
  else
    ActiveSupport::Concurrency::NullLock
  end
end

#migration_context ⇒ Object

:nodoc:



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

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

#migrations_paths ⇒ Object

:nodoc:



249
250
251
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 249

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) 


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

def prefetch_primary_key?(table_name = nil)
  false
end

#prepared_statements? ⇒ Boolean Also known as: prepared_statements

Returns:

  • (Boolean) 


265
266
267
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 265

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

#prepared_statements_disabled_cache ⇒ Object

:nodoc:



270
271
272
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 270

def prepared_statements_disabled_cache # :nodoc:
  ActiveSupport::IsolatedExecutionState[:active_record_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 or returns the value of current_preventing_writes.

Returns:

  • (Boolean) 


242
243
244
245
246
247
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 242

def preventing_writes?
  return true if replica?
  return false if connection_class.nil?

  connection_class.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.

Active Record cannot track if the database is getting modified using this client. If that is the case, generally you’ll want to invalidate the query cache using ActiveRecord::Base.clear_query_cache.



813
814
815
816
817
818
819
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 813

def raw_connection
  with_raw_connection do |conn|
    disable_lazy_transactions!
    @raw_connection_dirty = true
    conn
  end
end

#reconnect!(restore_transactions: false) ⇒ Object

Disconnects from the database if already connected, and establishes a new connection with the database. Implementors should define private #reconnect instead.



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
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 680

def reconnect!(restore_transactions: false)
  retries_available = connection_retries
  deadline = retry_deadline && Process.clock_gettime(Process::CLOCK_MONOTONIC) + retry_deadline

  @lock.synchronize do
    reconnect

    enable_lazy_transactions!
    @raw_connection_dirty = false
    @verified = true

    reset_transaction(restore: restore_transactions) do
      clear_cache!(new_connection: true)
      configure_connection
    end
  rescue => original_exception
    translated_exception = translate_exception_class(original_exception, nil, nil)
    retry_deadline_exceeded = deadline && deadline < Process.clock_gettime(Process::CLOCK_MONOTONIC)

    if !retry_deadline_exceeded && retries_available > 0
      retries_available -= 1

      if retryable_connection_error?(translated_exception)
        backoff(connection_retries - retries_available)
        retry
      end
    end

    @verified = false

    raise translated_exception
  end
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



634
635
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 634

def release_advisory_lock(lock_id) # :nodoc:
end

#rename_enum ⇒ Object

This is meant to be implemented by the adapters that support custom enum types



608
609
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 608

def rename_enum(*) # :nodoc:
end

#rename_enum_value ⇒ Object

This is meant to be implemented by the adapters that support custom enum types



616
617
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 616

def rename_enum_value(*) # :nodoc:
end

#replica? ⇒ Boolean

Returns:

  • (Boolean) 


214
215
216
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 214

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) 


768
769
770
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 768

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.

If a database driver or protocol does not support such a feature, implementors may alias this to #reconnect!. Otherwise, implementors should call super immediately after resetting the connection (and while still holding @lock).



742
743
744
745
746
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 742

def reset!
  clear_cache!(new_connection: true)
  reset_transaction
  configure_connection
end

#retry_deadline ⇒ Object 



226
227
228
229
230
231
232
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 226

def retry_deadline
  if @config[:retry_deadline]
    @config[:retry_deadline].to_f
  else
    nil
  end
end

#return_value_after_insert?(column) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


582
583
584
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 582

def return_value_after_insert?(column) # :nodoc:
  column.auto_incremented_by_db?
end

#role ⇒ Object

The role (e.g. :writing) for the current connection. In a non-multi role application, :writing is returned.



319
320
321
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 319

def role
  @pool.role
end

#savepoint_errors_invalidate_transactions? ⇒ Boolean

Do TransactionRollbackErrors on savepoints affect the parent transaction?

Returns:

  • (Boolean) 


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

def savepoint_errors_invalidate_transactions?
  false
end

#schema_cache ⇒ Object 



329
330
331
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 329

def schema_cache
  @schema_cache ||= BoundSchemaReflection.new(@pool.schema_reflection, self)
end

#schema_migration ⇒ Object

:nodoc:



257
258
259
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 257

def schema_migration # :nodoc:
  SchemaMigration.new(self)
end

#schema_version ⇒ Object

Returns the version identifier of the schema currently available in the database. This is generally equal to the number of the highest- numbered migration that has been executed, or 0 if no schema information is present / the database is empty.



880
881
882
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 880

def schema_version
  migration_context.current_version
end

#seconds_idle ⇒ Object

Seconds since this connection was returned to the pool



363
364
365
366
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 363

def seconds_idle # :nodoc:
  return 0 if in_use?
  Process.clock_gettime(Process::CLOCK_MONOTONIC) - @idle_since
end

#shard ⇒ Object

The shard (e.g. :default) for the current connection. In a non-sharded application, :default is returned.



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

def shard
  @pool.shard
end

#steal! ⇒ Object

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



350
351
352
353
354
355
356
357
358
359
360
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 350

def steal! # :nodoc:
  if in_use?
    if @owner != ActiveSupport::IsolatedExecutionState.context
      pool.send :remove_connection_from_thread_cache, self, @owner

      @owner = ActiveSupport::IsolatedExecutionState.context
    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) 


419
420
421
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 419

def supports_advisory_locks?
  false
end

#supports_bulk_alter? ⇒ Boolean

Returns:

  • (Boolean) 


399
400
401
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 399

def supports_bulk_alter?
  false
end

#supports_check_constraints? ⇒ Boolean

Does this adapter support creating check constraints?

Returns:

  • (Boolean) 


491
492
493
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 491

def supports_check_constraints?
  false
end

#supports_comments? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

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) 


531
532
533
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 531

def supports_comments_in_create?
  false
end

#supports_common_table_expressions? ⇒ Boolean

Returns:

  • (Boolean) 


550
551
552
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 550

def supports_common_table_expressions?
  false
end

#supports_concurrent_connections? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_concurrent_connections?
  true
end

#supports_datetime_with_precision? ⇒ Boolean

Does this adapter support datetime with precision?

Returns:

  • (Boolean) 


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

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) 


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

def supports_ddl_transactions?
  false
end

#supports_deferrable_constraints? ⇒ Boolean

Does this adapter support creating deferrable constraints?

Returns:

  • (Boolean) 


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

def supports_deferrable_constraints?
  false
end

#supports_exclusion_constraints? ⇒ Boolean

Does this adapter support creating exclusion constraints?

Returns:

  • (Boolean) 


496
497
498
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 496

def supports_exclusion_constraints?
  false
end

#supports_explain? ⇒ Boolean

Does this adapter support explain?

Returns:

  • (Boolean) 


455
456
457
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 455

def supports_explain?
  false
end

#supports_expression_index? ⇒ Boolean

Does this adapter support expression indices?

Returns:

  • (Boolean) 


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

def supports_expression_index?
  false
end

#supports_extensions? ⇒ Boolean

Does this adapter support database extensions?

Returns:

  • (Boolean) 


465
466
467
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 465

def supports_extensions?
  false
end

#supports_foreign_keys? ⇒ Boolean

Does this adapter support creating foreign key constraints?

Returns:

  • (Boolean) 


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

def supports_foreign_keys?
  false
end

#supports_foreign_tables? ⇒ Boolean

Does this adapter support foreign/external tables?

Returns:

  • (Boolean) 


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

def supports_foreign_tables?
  false
end

#supports_index_include? ⇒ Boolean

Does this adapter support including non-key columns?

Returns:

  • (Boolean) 


445
446
447
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 445

def supports_index_include?
  false
end

#supports_index_sort_order? ⇒ Boolean

Does this adapter support index sort order?

Returns:

  • (Boolean) 


435
436
437
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 435

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) 


471
472
473
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 471

def supports_indexes_in_create?
  false
end

#supports_insert_conflict_target? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_insert_conflict_target?
  false
end

#supports_insert_on_duplicate_skip? ⇒ Boolean

Returns:

  • (Boolean) 


562
563
564
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 562

def supports_insert_on_duplicate_skip?
  false
end

#supports_insert_on_duplicate_update? ⇒ Boolean

Returns:

  • (Boolean) 


566
567
568
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 566

def supports_insert_on_duplicate_update?
  false
end

#supports_insert_returning? ⇒ Boolean

Returns:

  • (Boolean) 


558
559
560
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 558

def supports_insert_returning?
  false
end

#supports_json? ⇒ Boolean

Does this adapter support JSON data type?

Returns:

  • (Boolean) 


521
522
523
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 521

def supports_json?
  false
end

#supports_lazy_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


554
555
556
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 554

def supports_lazy_transactions?
  false
end

#supports_materialized_views? ⇒ Boolean

Does this adapter support materialized views?

Returns:

  • (Boolean) 


511
512
513
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 511

def supports_materialized_views?
  false
end

#supports_nulls_not_distinct? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_nulls_not_distinct?
  false
end

#supports_optimizer_hints? ⇒ Boolean

Does this adapter support optimizer hints?

Returns:

  • (Boolean) 


546
547
548
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 546

def supports_optimizer_hints?
  false
end

#supports_partial_index? ⇒ Boolean

Does this adapter support partial indices?

Returns:

  • (Boolean) 


440
441
442
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 440

def supports_partial_index?
  false
end

#supports_partitioned_indexes? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_partitioned_indexes?
  false
end

#supports_restart_db_transaction? ⇒ Boolean

Returns:

  • (Boolean) 


414
415
416
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 414

def supports_restart_db_transaction?
  false
end

#supports_savepoints? ⇒ Boolean

Does this adapter support savepoints?

Returns:

  • (Boolean) 


404
405
406
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 404

def supports_savepoints?
  false
end

#supports_transaction_isolation? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

def supports_transaction_isolation?
  false
end

#supports_unique_constraints? ⇒ Boolean

Does this adapter support creating unique constraints?

Returns:

  • (Boolean) 


501
502
503
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 501

def supports_unique_constraints?
  false
end

#supports_validate_constraints? ⇒ Boolean

Does this adapter support creating invalid constraints?

Returns:

  • (Boolean) 


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

def supports_validate_constraints?
  false
end

#supports_views? ⇒ Boolean

Does this adapter support views?

Returns:

  • (Boolean) 


506
507
508
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 506

def supports_views?
  false
end

#supports_virtual_columns? ⇒ Boolean

Does this adapter support virtual columns?

Returns:

  • (Boolean) 


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

def supports_virtual_columns?
  false
end

#throw_away! ⇒ Object

Removes the connection from the pool and disconnect it.



749
750
751
752
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 749

def throw_away!
  pool.remove self
  disconnect!
end

#unprepared_statement ⇒ Object 



368
369
370
371
372
373
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 368

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) 


218
219
220
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 218

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

#valid_type?(type) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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

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.



775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 775

def verify!
  unless active?
    @lock.synchronize do
      if @unconfigured_connection
        @raw_connection = @unconfigured_connection
        @unconfigured_connection = nil
        configure_connection
        @verified = true
        return
      end

      reconnect!(restore_transactions: true)
    end
  end

  @verified = true
end

#with_instrumenter(instrumenter, &block) ⇒ Object

:nodoc:



198
199
200
201
202
203
204
205
206
 
# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 198

def with_instrumenter(instrumenter, &block) # :nodoc:
  Thread.handle_interrupt(EXCEPTION_NEVER) do
    previous_instrumenter = @instrumenter
    @instrumenter = instrumenter
    Thread.handle_interrupt(EXCEPTION_IMMEDIATE, &block)
  ensure
    @instrumenter = previous_instrumenter
  end
end