Class: ActiveRecord::ConnectionAdapters::AbstractAdapter

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

Overview

Active Record 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.lease_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

Constants included from ActiveSupport::Callbacks

ActiveSupport::Callbacks::CALLBACK_FILTER_TYPES

Instance Attribute Summary collapse

Attributes included from QueryCache

#query_cache

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, #query_cache_enabled, #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, #lookup_cast_type, #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 ActiveSupport::Concern

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

Methods included from DatabaseStatements

#add_transaction_record, #begin_db_transaction, #begin_deferred_transaction, #begin_isolated_db_transaction, #cacheable_query, #commit_db_transaction, #default_insert_value, #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, #raw_exec_query, #reset_isolation_level, #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, #disable_index, #distinct_relation_for_primary_key, #drop_join_table, #drop_table, #dump_schema_versions, #enable_index, #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, #options_include_default?, #primary_key, #quoted_columns_for_index, #remove_check_constraint, #remove_column, #remove_columns, #remove_constraint, #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

Methods included from ActiveSupport::Callbacks

#run_callbacks

Constructor Details

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

:nodoc:



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

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 Active Record 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
  @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
  @last_activity = nil
  @verified = false
end

Instance Attribute Details

#lock ⇒ Object (readonly)

Returns the value of attribute lock.



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

def lock
  @lock
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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

def logger
  @logger
end

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

Returns the value of attribute owner.



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

def owner
  @owner
end

#pool ⇒ Object

Returns the value of attribute pool.



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

def pool
  @pool
end

#visitor ⇒ Object (readonly)

Returns the value of attribute visitor.



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

def visitor
  @visitor
end

Class Method Details

.build_read_query_regexp(*parts) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 86

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) 


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

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

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

Opens a database console session.

Raises:

  • (NotImplementedError) 


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

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

.extended_type_map(default_timezone:) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 885

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:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 92

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:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 878

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 



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 65

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 55

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

.valid_type?(type) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 893

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

.validate_default_timezone(config) ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 73

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) 


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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 664

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 357

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



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

def add_enum_value(...) # :nodoc:
end

#advisory_locks_enabled? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 611

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

#async_enabled? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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

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.



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

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 822

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 818

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.



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 649

def check_all_foreign_keys_valid!
end

#check_if_write_query(sql) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 193

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:



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

def check_version # :nodoc:
end

#clean! ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 791

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.



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 747

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



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 838

def close
  pool.checkin self
end

#connect! ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 786

def connect!
  verify!
  self
end

#connected? ⇒ Boolean

Checks whether the connection to the database was established. This doesn’t include checking whether the database is actually capable of responding, i.e. whether the connection is stale.

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 657

def connected?
  !@raw_connection.nil?
end

#connection_descriptor ⇒ Object

:nodoc:



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

def connection_descriptor # :nodoc:
  @pool.connection_descriptor
end

#connection_retries ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 203

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



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

def create_enum(...) # :nodoc:
end

#create_virtual_table ⇒ Object

This is meant to be implemented by the adapters that support virtual tables



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

def create_virtual_table(*) # :nodoc:
end

#database_exists? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 366

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

#database_version ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 862

def database_version # :nodoc:
  pool.server_version(self)
end

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 842

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

#default_timezone ⇒ Object 



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

def default_timezone
  @default_timezone || ActiveRecord.default_timezone
end

#default_uniqueness_comparison(attribute, value) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 814

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



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

def disable_extension(name, **)
end

#disable_referential_integrity ⇒ Object

Override to turn off referential integrity while executing &block.



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 642

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 722

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

#disconnect! ⇒ Object

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



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 708

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



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 588

def drop_enum(...) # :nodoc:
end

#drop_virtual_table ⇒ Object

This is meant to be implemented by the adapters that support virtual tables



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

def drop_virtual_table(*) # :nodoc:
end

#enable_extension(name) ⇒ Object

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



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

def enable_extension(name, **)
end

#expire ⇒ Object

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



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

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.



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

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 619

def get_advisory_lock(lock_id) # :nodoc:
end

#get_database_version ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 859

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 635

def index_algorithms
  {}
end

#inspect ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 174

def inspect # :nodoc:
  name_field = " name=#{pool.db_config.name.inspect}" unless pool.db_config.name == "primary"
  shard_field = " shard=#{shard.inspect}" unless shard == :default

  "#<#{self.class.name}:#{'%#016x' % (object_id << 1)} env_name=#{pool.db_config.env_name.inspect}#{name_field} role=#{role.inspect}#{shard_field}>"
end

#lease ⇒ Object

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



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

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:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 181

def lock_thread=(lock_thread) # :nodoc:
  @lock =
  case lock_thread
  when Thread
    ActiveSupport::Concurrency::ThreadLoadInterlockAwareMonitor.new
  when Fiber
    ActiveSupport::Concurrency::LoadInterlockAwareMonitor.new
  else
    ActiveSupport::Concurrency::NullLock
  end
end

#native_database_types ⇒ Object

:nodoc:



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

def native_database_types # :nodoc:
  self.class.native_database_types
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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 406

def prefetch_primary_key?(table_name = nil)
  false
end

#prepared_statements? ⇒ Boolean Also known as: prepared_statements

Returns:

  • (Boolean) 


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

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

#prepared_statements_disabled_cache ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 239

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) 


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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 227

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

  connection_descriptor.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.



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 806

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.



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 670

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
    @last_activity = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    @verified = true

    reset_transaction(restore: restore_transactions) do
      clear_cache!(new_connection: true)
      attempt_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

    @last_activity = nil
    @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



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

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



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

def rename_enum(...) # :nodoc:
end

#rename_enum_value ⇒ Object

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



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

def rename_enum_value(...) # :nodoc:
end

#replica? ⇒ Boolean

Returns:

  • (Boolean) 


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

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 760

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).



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 734

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

#retry_deadline ⇒ Object 



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

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) 


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

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

#role ⇒ Object

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



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

def role
  @pool.role
end

#savepoint_errors_invalidate_transactions? ⇒ Boolean

Do TransactionRollbackErrors on savepoints affect the parent transaction?

Returns:

  • (Boolean) 


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

def savepoint_errors_invalidate_transactions?
  false
end

#schema_cache ⇒ Object 



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

def schema_cache
  @pool.schema_cache || (@schema_cache ||= BoundSchemaReflection.for_lone_connection(@pool.schema_reflection, 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.



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

def schema_version
  pool.migration_context.current_version
end

#seconds_idle ⇒ Object

Seconds since this connection was returned to the pool



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

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

#seconds_since_last_activity ⇒ Object

Seconds since this connection last communicated with the server



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

def seconds_since_last_activity # :nodoc:
  if @raw_connection && @last_activity
    Process.clock_gettime(Process::CLOCK_MONOTONIC) - @last_activity
  end
end

#shard ⇒ Object

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



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

def shard
  @pool.shard
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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 323

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) 


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

def supports_advisory_locks?
  false
end

#supports_bulk_alter? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_bulk_alter?
  false
end

#supports_check_constraints? ⇒ Boolean

Does this adapter support creating check constraints?

Returns:

  • (Boolean) 


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

def supports_check_constraints?
  false
end

#supports_comments? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 511

def supports_comments_in_create?
  false
end

#supports_common_table_expressions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 530

def supports_common_table_expressions?
  false
end

#supports_concurrent_connections? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_concurrent_connections?
  true
end

#supports_datetime_with_precision? ⇒ Boolean

Does this adapter support datetime with precision?

Returns:

  • (Boolean) 


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

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 375

def supports_ddl_transactions?
  false
end

#supports_deferrable_constraints? ⇒ Boolean

Does this adapter support creating deferrable constraints?

Returns:

  • (Boolean) 


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

def supports_deferrable_constraints?
  false
end

#supports_disabling_indexes? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_disabling_indexes?
  false
end

#supports_exclusion_constraints? ⇒ Boolean

Does this adapter support creating exclusion constraints?

Returns:

  • (Boolean) 


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

def supports_exclusion_constraints?
  false
end

#supports_explain? ⇒ Boolean

Does this adapter support explain?

Returns:

  • (Boolean) 


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

def supports_explain?
  false
end

#supports_expression_index? ⇒ Boolean

Does this adapter support expression indices?

Returns:

  • (Boolean) 


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

def supports_expression_index?
  false
end

#supports_extensions? ⇒ Boolean

Does this adapter support database extensions?

Returns:

  • (Boolean) 


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

def supports_extensions?
  false
end

#supports_foreign_keys? ⇒ Boolean

Does this adapter support creating foreign key constraints?

Returns:

  • (Boolean) 


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

def supports_foreign_keys?
  false
end

#supports_foreign_tables? ⇒ Boolean

Does this adapter support foreign/external tables?

Returns:

  • (Boolean) 


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

def supports_foreign_tables?
  false
end

#supports_index_include? ⇒ Boolean

Does this adapter support including non-key columns?

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 425

def supports_index_include?
  false
end

#supports_index_sort_order? ⇒ Boolean

Does this adapter support index sort order?

Returns:

  • (Boolean) 


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

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 451

def supports_indexes_in_create?
  false
end

#supports_insert_conflict_target? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_insert_conflict_target?
  false
end

#supports_insert_on_duplicate_skip? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_insert_on_duplicate_skip?
  false
end

#supports_insert_on_duplicate_update? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_insert_on_duplicate_update?
  false
end

#supports_insert_returning? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_insert_returning?
  false
end

#supports_json? ⇒ Boolean

Does this adapter support JSON data type?

Returns:

  • (Boolean) 


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

def supports_json?
  false
end

#supports_lazy_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_lazy_transactions?
  false
end

#supports_materialized_views? ⇒ Boolean

Does this adapter support materialized views?

Returns:

  • (Boolean) 


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

def supports_materialized_views?
  false
end

#supports_nulls_not_distinct? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_nulls_not_distinct?
  false
end

#supports_optimizer_hints? ⇒ Boolean

Does this adapter support optimizer hints?

Returns:

  • (Boolean) 


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

def supports_optimizer_hints?
  false
end

#supports_partial_index? ⇒ Boolean

Does this adapter support partial indices?

Returns:

  • (Boolean) 


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

def supports_partial_index?
  false
end

#supports_partitioned_indexes? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_partitioned_indexes?
  false
end

#supports_restart_db_transaction? ⇒ Boolean

Returns:

  • (Boolean) 


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

def supports_restart_db_transaction?
  false
end

#supports_savepoints? ⇒ Boolean

Does this adapter support savepoints?

Returns:

  • (Boolean) 


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

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 440

def supports_transaction_isolation?
  false
end

#supports_unique_constraints? ⇒ Boolean

Does this adapter support creating unique constraints?

Returns:

  • (Boolean) 


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

def supports_unique_constraints?
  false
end

#supports_validate_constraints? ⇒ Boolean

Does this adapter support creating invalid constraints?

Returns:

  • (Boolean) 


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

def supports_validate_constraints?
  false
end

#supports_views? ⇒ Boolean

Does this adapter support views?

Returns:

  • (Boolean) 


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

def supports_views?
  false
end

#supports_virtual_columns? ⇒ Boolean

Does this adapter support virtual columns?

Returns:

  • (Boolean) 


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

def supports_virtual_columns?
  false
end

#throw_away! ⇒ Object

Removes the connection from the pool and disconnect it.



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 741

def throw_away!
  pool.remove self
  disconnect!
end

#unprepared_statement ⇒ Object 



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

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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 262

def valid_type?(type) # :nodoc:
  self.class.valid_type?(type)
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 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 767

def verify!
  unless active?
    @lock.synchronize do
      if @unconfigured_connection
        @raw_connection = @unconfigured_connection
        @unconfigured_connection = nil
        attempt_configure_connection
        @last_activity = Process.clock_gettime(Process::CLOCK_MONOTONIC)
        @verified = true
        return
      end

      reconnect!(restore_transactions: true)
    end
  end

  @verified = true
end

#verify_timeout ⇒ Object 



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# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 207

def verify_timeout
  (@config[:verify_timeout] || 2).to_i
end