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/

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:



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

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.



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

def lock
  @lock
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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

def logger
  @logger
end

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

Returns the value of attribute owner.



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

def owner
  @owner
end

#pool ⇒ Object

Returns the value of attribute pool.



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

def pool
  @pool
end

#visitor ⇒ Object (readonly)

Returns the value of attribute visitor.



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

def visitor
  @visitor
end

Class Method Details

.build_read_query_regexp(*parts) ⇒ Object

:nodoc:



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

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

.database_exists?(config) ⇒ Boolean

Does the database for this adapter exist?

Returns:

  • (Boolean)

Raises:

  • (NotImplementedError) 


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

def self.database_exists?(config)
  raise NotImplementedError
end

.quoted_column_names ⇒ Object

:nodoc:



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

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

.quoted_table_names ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 114

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

.type_cast_config_to_boolean(config) ⇒ Object 



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 97

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

.type_cast_config_to_integer(config) ⇒ Object 



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 87

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) 


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

def active?
end

#adapter_name ⇒ Object

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



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 279

def adapter_name
  self.class::ADAPTER_NAME
end

#advisory_locks_enabled? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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

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.



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

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:



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

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:



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

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

#check_version ⇒ Object

:nodoc:



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

def check_version # :nodoc:
end

#clear_cache! ⇒ Object

Clear any caching the database adapter may be doing.



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

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

#close ⇒ Object

Check the connection back in to the connection pool



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

def close
  pool.checkin self
end

#column_name_for_operation(operation, node) ⇒ Object

:nodoc:



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

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

#database_version ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 615

def database_version # :nodoc:
  schema_cache.database_version
end

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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

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

#default_uniqueness_comparison(attribute, value, klass) ⇒ Object

:nodoc:



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

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



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

def disable_extension(name)
end

#disable_referential_integrity ⇒ Object

Override to turn off referential integrity while executing &block.



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

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.



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

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.



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 504

def disconnect!
  clear_cache!
  reset_transaction
end

#enable_extension(name) ⇒ Object

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



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

def enable_extension(name)
end

#expire ⇒ Object

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



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

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.



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

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



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

def get_advisory_lock(lock_id) # :nodoc:
end

#get_database_version ⇒ Object

:nodoc:



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

def get_database_version # :nodoc:
end

#index_algorithms ⇒ Object

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



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 475

def index_algorithms
  {}
end

#lease ⇒ Object

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



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 211

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:



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 160

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

#migrations_paths ⇒ Object

:nodoc:



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

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) 


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

def prefetch_primary_key?(table_name = nil)
  false
end

#prepared_statements ⇒ Object 



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 179

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

#prepared_statements_disabled_cache ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 183

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) 


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

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.



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

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.



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

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



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

def release_advisory_lock(lock_id) # :nodoc:
end

#replica? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 144

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) 


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

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.



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

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

#schema_cache ⇒ Object 



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 226

def schema_cache
  @pool.get_schema_cache(self)
end

#schema_cache=(cache) ⇒ Object 



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 230

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

#schema_migration ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 164

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

                          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



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

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)



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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 252

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) 


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

def supports_advisory_locks?
  false
end

#supports_bulk_alter? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_bulk_alter?
  false
end

#supports_comments? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

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) 


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

def supports_comments_in_create?
  false
end

#supports_common_table_expressions? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_common_table_expressions?
  false
end

#supports_datetime_with_precision? ⇒ Boolean

Does this adapter support datetime with precision?

Returns:

  • (Boolean) 


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

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) 


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

def supports_ddl_transactions?
  false
end

#supports_explain? ⇒ Boolean

Does this adapter support explain?

Returns:

  • (Boolean) 


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

def supports_explain?
  false
end

#supports_expression_index? ⇒ Boolean

Does this adapter support expression indices?

Returns:

  • (Boolean) 


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

def supports_expression_index?
  false
end

#supports_extensions? ⇒ Boolean

Does this adapter support database extensions?

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/abstract_adapter.rb', line 341

def supports_extensions?
  false
end

#supports_foreign_keys? ⇒ Boolean

Does this adapter support creating foreign key constraints?

Returns:

  • (Boolean) 


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

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) 


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

def supports_foreign_keys_in_create?
  supports_foreign_keys?
end

#supports_foreign_tables? ⇒ Boolean

Does this adapter support foreign/external tables?

Returns:

  • (Boolean) 


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

def supports_foreign_tables?
  false
end

#supports_index_sort_order? ⇒ Boolean

Does this adapter support index sort order?

Returns:

  • (Boolean) 


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

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) 


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

def supports_indexes_in_create?
  false
end

#supports_insert_conflict_target? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_insert_conflict_target?
  false
end

#supports_insert_on_duplicate_skip? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_insert_on_duplicate_skip?
  false
end

#supports_insert_on_duplicate_update? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_insert_on_duplicate_update?
  false
end

#supports_insert_returning? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_insert_returning?
  false
end

#supports_json? ⇒ Boolean

Does this adapter support json data type?

Returns:

  • (Boolean) 


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

def supports_json?
  false
end

#supports_lazy_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_lazy_transactions?
  false
end

#supports_materialized_views? ⇒ Boolean

Does this adapter support materialized views?

Returns:

  • (Boolean) 


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

def supports_materialized_views?
  false
end

#supports_multi_insert? ⇒ Boolean

Does this adapter support multi-value insert?

Returns:

  • (Boolean) 


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

def supports_multi_insert?
  true
end

#supports_optimizer_hints? ⇒ Boolean

Does this adapter support optimizer hints?

Returns:

  • (Boolean) 


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

def supports_optimizer_hints?
  false
end

#supports_partial_index? ⇒ Boolean

Does this adapter support partial indices?

Returns:

  • (Boolean) 


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

def supports_partial_index?
  false
end

#supports_savepoints? ⇒ Boolean

Does this adapter support savepoints?

Returns:

  • (Boolean) 


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

def supports_savepoints?
  false
end

#supports_transaction_isolation? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

def supports_transaction_isolation?
  false
end

#supports_validate_constraints? ⇒ Boolean

Does this adapter support creating invalid constraints?

Returns:

  • (Boolean) 


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

def supports_validate_constraints?
  false
end

#supports_views? ⇒ Boolean

Does this adapter support views?

Returns:

  • (Boolean) 


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

def supports_views?
  false
end

#supports_virtual_columns? ⇒ Boolean

Does this adapter support virtual columns?

Returns:

  • (Boolean) 


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

def supports_virtual_columns?
  false
end

#unprepared_statement ⇒ Object 



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

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) 


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

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.



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

def verify!
  reconnect! unless active?
end