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Class: ActiveRecord::ConnectionAdapters::AbstractAdapter

Relationships & Source Files
Namespace Children
Classes:
Version
Extension / Inclusion / Inheritance Descendants
Subclasses:
AbstractMysqlAdapter, Mysql2Adapter, PostgreSQLAdapter, SQLite3Adapter, TrilogyAdapter
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::ActiveSupport::DescendantsTracker
Instance Chain:
self, Savepoints, ::ActiveRecord::QueryCache, DatabaseLimits, Quoting, DatabaseStatements, SchemaStatements, ::ActiveRecord::Migration::JoinTable, ::ActiveSupport::Callbacks
Inherits: Object
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.

Constant Summary

::ActiveSupport::Callbacks - Included

CALLBACK_FILTER_TYPES

DatabaseStatements - Included

DEFAULT_INSERT_VALUE, HIGH_PRECISION_CURRENT_TIMESTAMP

::ActiveSupport::Callbacks - Attributes & Methods

Class Method Summary

::ActiveSupport::DescendantsTracker - self

descendants, subclasses, clear, disable_clear!, reject!

Instance Attribute Summary

DatabaseStatements - Included

#begin_transaction, #commit_transaction, #current_transaction, #dirty_current_transaction, #materialize_transactions, #open_transactions, #rollback_transaction, #transaction_open?, #within_new_transaction, #transaction_manager

SchemaStatements - Included

#use_foreign_keys?, #foreign_keys_enabled?

Instance Method Summary

Savepoints - Included

#create_savepoint, #current_savepoint_name, #exec_rollback_to_savepoint, #release_savepoint

DatabaseLimits - Included

#index_name_length

Returns the maximum length of an index name.
#table_alias_length

Returns the maximum length of a table alias.
#table_name_length

Returns the maximum length of a table name.
#bind_params_length, #max_identifier_length

Quoting - Included

#quote

Quotes the column value to help prevent SQL injection attacks.
#quote_column_name

Quotes the column name.
#quote_string

Quotes a string, escaping any ‘ (single quote) and \ (backslash) characters.
#quote_table_name

Quotes the table name.
#quote_table_name_for_assignment

Override to return the quoted table name for assignment.
#quoted_date

Quote date/time values for use in SQL input.
#quoted_false, #quoted_true,
#type_cast

Cast a value to a type that the database understands.
#unquoted_false, #unquoted_true, #lookup_cast_type, #type_casted_binds,
#cast_bound_value

Cast a value to be used as a bound parameter of unknown type.
#lookup_cast_type_from_column

If you are having to call this function, you are likely doing something wrong.
#quote_default_expression, #quoted_binary, #quoted_time, #sanitize_as_sql_comment

DatabaseStatements - Included

#add_transaction_record

Register a record with the current transaction so that its after_commit and after_rollback callbacks can be called.
#begin_db_transaction

Begins the transaction (and turns off auto-committing).
#begin_isolated_db_transaction

Begins the transaction with the isolation level set.
#commit_db_transaction

Commits the transaction (and turns on auto-committing).
#create

Alias for DatabaseStatements#insert.
#default_sequence_name,
#delete

Executes the delete statement and returns the number of rows affected.
#disable_lazy_transactions!, #empty_insert_statement_value, #enable_lazy_transactions!,
#exec_delete

Executes delete sql statement in the context of this connection using binds as the bind substitutes.
#exec_insert

Executes insert sql statement in the context of this connection using binds as the bind substitutes.
#exec_query

Executes sql statement in the context of this connection using binds as the bind substitutes.
#exec_update

Executes update sql statement in the context of this connection using binds as the bind substitutes.
#execute

Executes the SQL statement in the context of this connection and returns the raw result from the connection adapter.
#high_precision_current_timestamp

Returns an ::Arel SQL literal for the CURRENT_TIMESTAMP for usage with arbitrary precision date/time columns.
#initialize,
#insert

Executes an INSERT query and returns the new record’s ID.
#insert_fixture

Inserts the given fixture into the table.
#insert_fixtures_set,
#reset_isolation_level

Hook point called after an isolated DB transaction is committed or rolled back.
#reset_sequence!

Set the sequence to the max value of the table’s column.
#restart_db_transaction,
#rollback_db_transaction

Rolls back the transaction (and turns on auto-committing).
#rollback_to_savepoint,
#sanitize_limit

Sanitizes the given LIMIT parameter in order to prevent SQL injection.
#select_all

Returns an ::ActiveRecord::Result instance.
#select_one

Returns a record hash with the column names as keys and column values as values.
#select_rows

Returns an array of arrays containing the field values.
#select_value

Returns a single value from a record.
#select_values

Returns an array of the values of the first column in a select:
#to_sql

Converts an arel AST to SQL.
#transaction

Runs the given block in a database transaction, and returns the result of the block.
#transaction_isolation_levels,
#truncate

Executes the truncate statement.
#update

Executes the update statement and returns the number of rows affected.
#write_query?

Determines whether the SQL statement is a write query.
#affected_rows, #arel_from_relation, #build_fixture_sql, #build_fixture_statements, #build_truncate_statement, #build_truncate_statements,
#cast_result

Receive a native adapter result object and returns an ::ActiveRecord::Result object.
#combine_multi_statements, #default_insert_value, #execute_batch, #extract_table_ref_from_insert_sql,
#internal_execute

Same as #internal_exec_query, but yields a native adapter result.
#last_inserted_id, #perform_query, #preprocess_query,
#raw_execute

Lowest level way to execute a query.
#returning_column_values,
#select

Returns an ::ActiveRecord::Result instance.
#single_value_from_rows, #begin_deferred_transaction,
#cacheable_query

This is used in the ::ActiveRecord::StatementCache object.
#exec_insert_all, #exec_restart_db_transaction, #exec_rollback_db_transaction, #explain,
#internal_exec_query

Execute a query and returns an ::ActiveRecord::Result
#mark_transaction_written_if_write, #query, #query_value, #query_values,
#raw_exec_query

Same as raw_execute but returns an ::ActiveRecord::Result object.
#reset_transaction, #truncate_tables,
#with_yaml_fallback

::ActiveRecord::Fixture value is quoted by ::Arel, however scalar values are not quotable.
#sql_for_insert, #to_sql_and_binds

SchemaStatements - Included

#add_belongs_to

Alias for SchemaStatements#add_reference.
#add_check_constraint

Adds a new check constraint to the table.
#add_column

Add a new type column named column_name to table_name.
#add_foreign_key

Adds a new foreign key.
#add_index

Adds a new index to the table.
#add_reference

Adds a reference.
#add_timestamps

Adds timestamps (created_at and updated_at) columns to table_name.
#assume_migrated_upto_version,
#build_create_table_definition

Returns a TableDefinition object containing information about the table that would be created if the same arguments were passed to #create_table.
#change_column

Changes the column’s definition according to the new options.
#change_column_comment

Changes the comment for a column or removes it if nil.
#change_column_default

Sets a new default value for a column:
#change_column_null

Sets or removes a NOT NULL constraint on a column.
#change_table

A block for changing columns in table.
#change_table_comment

Changes the comment for a table or removes it if nil.
#check_constraint_exists?

Checks to see if a check constraint exists on a table for a given check constraint definition.
#check_constraints

Returns an array of check constraints for the given table.
#column_exists?

Checks to see if a column exists in a given table.
#columns

Returns an array of Column objects for the table specified by table_name.
#create_join_table

Creates a new join table with the name created using the lexical order of the first two arguments.
#create_table

Creates a new table with the name table_name.
#data_source_exists?

Checks to see if the data source name exists on the database.
#data_sources

Returns the relation names usable to back Active Record models.
#drop_join_table

Drops the join table specified by the given arguments.
#drop_table

Drops a table or tables from the database.
#foreign_key_exists?

Checks to see if a foreign key exists on a table for a given foreign key definition.
#foreign_keys

Returns an array of foreign keys for the given table.
#index_exists?

Checks to see if an index exists on a table for a given index definition.
#index_name_exists?

Verifies the existence of an index with a given name.
#indexes

Returns an array of indexes for the given table.
#max_index_name_size

Returns the maximum length of an index name in bytes.
#native_database_types

Returns a hash of mappings from the abstract data types to the native database types.
#options_include_default?,
#primary_key

Returns just a table’s primary key.
#remove_belongs_to

Alias for SchemaStatements#remove_reference.
#remove_check_constraint

Removes the given check constraint from the table.
#remove_column

Removes the column from the table definition.
#remove_columns

Removes the given columns from the table definition.
#remove_foreign_key

Removes the given foreign key from the table.
#remove_index

Removes the given index from the table.
#remove_reference

Removes the reference(s).
#remove_timestamps

Removes the timestamp columns (created_at and updated_at) from the table definition.
#rename_column

Renames a column.
#rename_index

Renames an index.
#rename_table

Renames a table.
#table_alias_for

Truncates a table alias according to the limits of the current adapter.
#table_comment

Returns the table comment that’s stored in database metadata.
#table_exists?

Checks to see if the table table_name exists on the database.
#table_options,
#tables

Returns an array of table names defined in the database.
#view_exists?

Checks to see if the view view_name exists on the database.
#views

Returns an array of view names defined in the database.
#add_column_for_alter, #add_index_sort_order,
#add_options_for_index_columns

Overridden by the MySQL adapter for supporting index lengths and by the PostgreSQL adapter for supporting operator classes.
#add_timestamps_for_alter, #can_remove_index_by_name?, #change_column_default_for_alter, #check_constraint_for, #check_constraint_for!, #check_constraint_name, #column_options_keys, #create_alter_table, #create_table_definition, #data_source_sql,
#expression_column_name?

Try to identify whether the given column name is an expression.
#extract_foreign_key_action,
#extract_new_comment_value

Alias for SchemaStatements#extract_new_default_value.
#extract_new_default_value, #fetch_type_metadata, #foreign_key_for, #foreign_key_for!, #foreign_key_name, #generate_index_name, #index_column_names, #index_name_for_remove, #index_name_options, #insert_versions_sql, #options_for_index_columns, #quoted_scope, #reference_name_for_table, #remove_column_for_alter, #remove_columns_for_alter, #remove_timestamps_for_alter, #rename_column_indexes, #rename_column_sql, #rename_table_indexes, #strip_table_name_prefix_and_suffix, #validate_change_column_null_argument!, #validate_create_table_options!, #validate_index_length!, #validate_table_length!, #add_columns, #add_index_options,
#build_add_column_definition

Builds an AlterTable object for adding a column to a table.
#build_change_column_default_definition

Builds a ChangeColumnDefaultDefinition object.
#build_create_index_definition

Builds a CreateIndexDefinition object.
#build_create_join_table_definition

Builds a TableDefinition object for a join table.
#bulk_change_table, #check_constraint_options,
#columns_for_distinct

Given a set of columns and an ORDER BY clause, returns the columns for a SELECT DISTINCT.
#create_schema_dumper, #distinct_relation_for_primary_key, #dump_schema_information, #foreign_key_column_for, #foreign_key_options, #index_algorithm, #index_name, #internal_string_options_for_primary_key, #quoted_columns_for_index, #remove_constraint,
#schema_creation

Returns an instance of SchemaCreation, which can be used to visit a schema definition object and return DDL.
#type_to_sql, #update_table_definition, #valid_column_definition_options, #valid_primary_key_options, #valid_table_definition_options

::ActiveRecord::Migration::JoinTable - Included

#find_join_table_name, #join_table_name

::ActiveSupport::Callbacks - Included

#run_callbacks

Runs the callbacks for the given event.
#halted_callback_hook

A hook invoked every time a before callback is halted.

Constructor Details

.new(config_or_deprecated_connection, deprecated_logger = nil, deprecated_connection_options = nil, deprecated_config = nil) ⇒ AbstractAdapter

This method is for internal use only.
[ GitHub ] 

  


# 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
  @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


  







Class Attribute Details



  

    .__callbacks   (rw)
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/callbacks.rb', line 69



class_attribute :__callbacks, instance_writer: false, instance_predicate: false, default: {}


  







Class Method Details



  

    .build_read_query_regexp(*parts)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# 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?


  





  


  [ GitHub ]


  

  


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



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


  








  

    .dbconsole(config, options = {})  
  



  

    

Opens a database console session.


  





  
Raises:


    
  
  • 
    (NotImplementedError)
  
    • 





  [ GitHub ]


  

  


# 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:)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 876



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


  








  

    .extract_limit(sql_type)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 936



def extract_limit(sql_type)
  $1.to_i if sql_type =~ /\((.*)\)/
end


  








  

    .extract_precision(sql_type)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 932



def extract_precision(sql_type)
  $1.to_i if sql_type =~ /\((\d)(,\d)?\)/
end


  








  

    .extract_scale(sql_type)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 925



def extract_scale(sql_type)
  case sql_type
  when /\((\d+)\)/ then 0
  when /\((\d)(,(\d))\)/ then $3.to_i
  end
end


  








  

    .find_cmd_and_exec(commands, *args)  
  

  [ GitHub ]


  

  


# 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


  








  

    .initialize_type_map(m)   (private)
  

  [ GitHub ]


  

  


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



def initialize_type_map(m)
  register_class_with_limit m, %r(boolean)i,       Type::Boolean
  register_class_with_limit m, %r(char)i,          Type::String
  register_class_with_limit m, %r(binary)i,        Type::Binary
  register_class_with_limit m, %r(text)i,          Type::Text
  register_class_with_precision m, %r(date)i,      Type::Date
  register_class_with_precision m, %r(time)i,      Type::Time
  register_class_with_precision m, %r(datetime)i,  Type::DateTime
  register_class_with_limit m, %r(float)i,         Type::Float
  register_class_with_limit m, %r(int)i,           Type::Integer

  m.alias_type %r(blob)i,      "binary"
  m.alias_type %r(clob)i,      "text"
  m.alias_type %r(timestamp)i, "datetime"
  m.alias_type %r(numeric)i,   "decimal"
  m.alias_type %r(number)i,    "decimal"
  m.alias_type %r(double)i,    "float"

  m.register_type %r(^json)i, Type::Json.new

  m.register_type(%r(decimal)i) do |sql_type|
    scale = extract_scale(sql_type)
    precision = extract_precision(sql_type)

    if scale == 0
      # FIXME: Remove this class as well
      Type::DecimalWithoutScale.new(precision: precision)
    else
      Type::Decimal.new(precision: precision, scale: scale)
    end
  end
end


  








  

    .register_class_with_limit(mapping, key, klass)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 918



def register_class_with_limit(mapping, key, klass)
  mapping.register_type(key) do |*args|
    limit = extract_limit(args.last)
    klass.new(limit: limit)
  end
end


  








  

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

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


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



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)  
  

  [ GitHub ]


  

  


# 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)  
  

  [ GitHub ]


  

  


# 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


  








  

    .validate_default_timezone(config)  
  

  [ GitHub ]


  

  


# 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 Attribute Details



  

    #__callbacks   (readonly)
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/callbacks.rb', line 69



class_attribute :__callbacks, instance_writer: false, instance_predicate: false, default: {}


  








  

    #active?  ⇒ Boolean  (readonly)
  



  

    

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.


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 658



def active?
end


  








  

    #advisory_locks_enabled?  ⇒ Boolean  (readonly)
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


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



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


  








  

    #async_enabled?  ⇒ Boolean  (readonly)
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


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



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


  








  

    #connected?  ⇒ Boolean  (readonly)
  



  

    

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.


  





  


  [ GitHub ]


  

  


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



def connected?
  !@raw_connection.nil?
end


  








  

    #database_exists?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



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


  








  

    #in_use?   (readonly)
  



  

    

Alias for #owner.


  



  [ GitHub ]


  

  


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



alias :in_use? :owner


  








  

    #lock   (readonly)
  

  [ GitHub ]


  

  


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



attr_reader :visitor, :owner, :logger, :lock


  








  

    #lock_thread=(lock_thread)   (writeonly)
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# 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


  








  

    #logger   (readonly)
  

  [ GitHub ]


  

  


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



attr_reader :visitor, :owner, :logger, :lock


  








  

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

  [ GitHub ]


  

  


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



attr_reader :visitor, :owner, :logger, :lock


  








  

    #pool   (rw)
  

  [ GitHub ]


  

  


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



attr_reader :pool


  








  

    #pool=(value)   (rw)
  

  [ GitHub ]


  

  


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



def pool=(value)
  return if value.eql?(@pool)
  @schema_cache = nil
  @pool = value
end


  








  

    #prepared_statements   (readonly)
  



  

    

Alias for #prepared_statements?.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 246



alias :prepared_statements :prepared_statements?


  








  

    #preventing_writes?  ⇒ Boolean  (readonly)
  



  

    

Determines whether writes are currently being prevented.



Returns true if the connection is a replica or returns the value of current_preventing_writes.


  





  


  [ GitHub ]


  

  


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



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

  connection_class.current_preventing_writes
end


  








  

    #reconnect_can_restore_state?  ⇒ Boolean  (readonly, private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 945



def reconnect_can_restore_state?
  transaction_manager.restorable? && !@raw_connection_dirty
end


  








  

    #replica?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 212



def replica?
  @config[:replica] || false
end


  








  

    #requires_reloading?  ⇒ Boolean  (readonly)
  



  

    

Returns true if its required to reload the connection between requests for development mode.


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 752



def requires_reloading?
  false
end


  








  

    #savepoint_errors_invalidate_transactions?  ⇒ Boolean  (readonly)
  



  

    

Do TransactionRollbackErrors on savepoints affect the parent transaction?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 388



def savepoint_errors_invalidate_transactions?
  false
end


  








  

    #supports_advisory_locks?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support application-enforced advisory locking?


  





  


  [ GitHub ]


  

  


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



def supports_advisory_locks?
  false
end


  








  

    #supports_bulk_alter?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



def supports_bulk_alter?
  false
end


  








  

    #supports_check_constraints?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support creating check constraints?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 469



def supports_check_constraints?
  false
end


  








  

    #supports_comments?  ⇒ Boolean  (readonly)
  



  

    

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


  





  


  [ GitHub ]


  

  


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



def supports_comments?
  false
end


  








  

    #supports_comments_in_create?  ⇒ Boolean  (readonly)
  



  

    

Can comments for tables, columns, and indexes be specified in create/alter table statements?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 509



def supports_comments_in_create?
  false
end


  








  

    #supports_common_table_expressions?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



def supports_common_table_expressions?
  false
end


  








  

    #supports_concurrent_connections?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



def supports_concurrent_connections?
  true
end


  








  

    #supports_datetime_with_precision?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support datetime with precision?


  





  


  [ GitHub ]


  

  


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



def supports_datetime_with_precision?
  false
end


  








  

    #supports_ddl_transactions?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support DDL rollbacks in transactions? That is, would CREATE TABLE or ALTER TABLE get rolled back by a transaction?


  





  


  [ GitHub ]


  

  


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



def supports_ddl_transactions?
  false
end


  








  

    #supports_deferrable_constraints?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support creating deferrable constraints?


  





  


  [ GitHub ]


  

  


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



def supports_deferrable_constraints?
  false
end


  








  

    #supports_exclusion_constraints?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support creating exclusion constraints?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 474



def supports_exclusion_constraints?
  false
end


  








  

    #supports_explain?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support explain?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 433



def supports_explain?
  false
end


  








  

    #supports_expression_index?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support expression indices?


  





  


  [ GitHub ]


  

  


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



def supports_expression_index?
  false
end


  








  

    #supports_extensions?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support database extensions?


  





  


  [ GitHub ]


  

  


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



def supports_extensions?
  false
end


  








  

    #supports_foreign_keys?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support creating foreign key constraints?


  





  


  [ GitHub ]


  

  


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



def supports_foreign_keys?
  false
end


  








  

    #supports_foreign_tables?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support foreign/external tables?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 519



def supports_foreign_tables?
  false
end


  








  

    #supports_index_include?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support including non-key columns?


  





  


  [ GitHub ]


  

  


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



def supports_index_include?
  false
end


  








  

    #supports_index_sort_order?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support index sort order?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 413



def supports_index_sort_order?
  false
end


  








  

    #supports_indexes_in_create?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support creating indexes in the same statement as creating the table?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 449



def supports_indexes_in_create?
  false
end


  








  

    #supports_insert_conflict_target?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



def supports_insert_conflict_target?
  false
end


  








  

    #supports_insert_on_duplicate_skip?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 540



def supports_insert_on_duplicate_skip?
  false
end


  








  

    #supports_insert_on_duplicate_update?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



def supports_insert_on_duplicate_update?
  false
end


  








  

    #supports_insert_returning?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



def supports_insert_returning?
  false
end


  








  

    #supports_json?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support JSON data type?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 499



def supports_json?
  false
end


  








  

    #supports_lazy_transactions?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



def supports_lazy_transactions?
  false
end


  








  

    #supports_materialized_views?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support materialized views?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 489



def supports_materialized_views?
  false
end


  








  

    #supports_nulls_not_distinct?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



def supports_nulls_not_distinct?
  false
end


  








  

    #supports_optimizer_hints?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support optimizer hints?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 524



def supports_optimizer_hints?
  false
end


  








  

    #supports_partial_index?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support partial indices?


  





  


  [ GitHub ]


  

  


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



def supports_partial_index?
  false
end


  








  

    #supports_partitioned_indexes?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 408



def supports_partitioned_indexes?
  false
end


  








  

    #supports_restart_db_transaction?  ⇒ Boolean  (readonly)
  

  [ GitHub ]


  

  


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



def supports_restart_db_transaction?
  false
end


  








  

    #supports_savepoints?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support savepoints?


  





  


  [ GitHub ]


  

  


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



def supports_savepoints?
  false
end


  








  

    #supports_transaction_isolation?  ⇒ Boolean  (readonly)
  



  

    

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


  





  


  [ GitHub ]


  

  


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



def supports_transaction_isolation?
  false
end


  








  

    #supports_unique_constraints?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support creating unique constraints?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 479



def supports_unique_constraints?
  false
end


  








  

    #supports_validate_constraints?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support creating invalid constraints?


  





  


  [ GitHub ]


  

  


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



def supports_validate_constraints?
  false
end


  








  

    #supports_views?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support views?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 484



def supports_views?
  false
end


  








  

    #supports_virtual_columns?  ⇒ Boolean  (readonly)
  



  

    

Does this adapter support virtual columns?


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 514



def supports_virtual_columns?
  false
end


  








  

    #visitor   (readonly)
  

  [ GitHub ]


  

  


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



attr_reader :visitor, :owner, :logger, :lock


  







Instance Method Details



  

    #adapter_name  
  



  

    

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


  



  [ GitHub ]


  

  


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



def adapter_name
  self.class::ADAPTER_NAME
end


  








  

    #add_enum_value  
  

  

    This method is for internal use only.
  



  

    

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


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 590



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


  








  

    #any_raw_connection   (private)
  



  

    

Returns a raw connection for internal use with methods that are known to both be thread-safe and not rely upon actual server communication. This is useful for e.g. string escaping methods.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1083



def any_raw_connection
  @raw_connection || valid_raw_connection
end


  








  

    #arel_visitor   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1180



def arel_visitor
  Arel::Visitors::ToSql.new(self)
end


  








  

    #backoff(counter)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1072



def backoff(counter)
  sleep 0.1 * counter
end


  








  

    #build_insert_sql(insert)  
  

  

    This method is for internal use only.
  



  

    

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.


  



  [ GitHub ]


  

  


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



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


  








  

    #build_result(columns:, rows:, column_types: nil)   (private)
  



  

    

Builds the result object.



This is an internal hook to make possible connection adapters to build custom result objects with connection-specific data.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1191



def build_result(columns:, rows:, column_types: nil)
  ActiveRecord::Result.new(columns, rows, column_types)
end


  








  

    #build_statement_pool   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1184



def build_statement_pool
end


  








  

    #can_perform_case_insensitive_comparison_for?(column)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


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



def can_perform_case_insensitive_comparison_for?(column)
  true
end


  








  

    #case_insensitive_comparison(attribute, value)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 813



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)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 809



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


  








  

    #check_all_foreign_keys_valid!  
  



  

    

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


  



  [ GitHub ]


  

  


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



def check_all_foreign_keys_valid!
end


  








  

    #check_if_write_query(sql)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


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



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  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 857



def check_version # :nodoc:
end


  








  

    #clean!  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 782



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


  








  

    #clear_cache!(new_connection: false)  
  



  

    

Clear any caching the database adapter may be doing.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 739



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


  








  

    #close  
  



  

    

Check the connection back in to the connection pool


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 829



def close
  pool.checkin self
end


  








  

    #collector   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1166



def collector
  if prepared_statements
    Arel::Collectors::Composite.new(
      Arel::Collectors::SQLString.new,
      Arel::Collectors::Bind.new,
    )
  else
    Arel::Collectors::SubstituteBinds.new(
      self,
      Arel::Collectors::SQLString.new,
    )
  end
end


  








  

    #column_for(table_name, column_name)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1155



def column_for(table_name, column_name)
  column_name = column_name.to_s
  columns(table_name).detect { |c| c.name == column_name } ||
    raise(ActiveRecordError, "No such column: #{table_name}.#{column_name}")
end


  








  

    #column_for_attribute(attribute)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1161



def column_for_attribute(attribute)
  table_name = attribute.relation.name
  schema_cache.columns_hash(table_name)[attribute.name.to_s]
end


  








  

    #configure_connection   (private)
  



  

    

Perform any necessary initialization upon the newly-established connection settings, run queries to configure any application-global “session” variables, etc.



Implementations may assume this method will only be called while holding @lock (or from #initialize).


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1202



def configure_connection
  check_version
end


  








  

    #connect!  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 777



def connect!
  verify!
  self
end


  








  

    #connection_class  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


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



def connection_class # :nodoc:
  @pool.connection_class
end


  








  

    #connection_retries  
  

  [ GitHub ]


  

  


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



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


  








  

    #create_enum  
  

  

    This method is for internal use only.
  



  

    

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


  



  [ GitHub ]


  

  


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



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


  








  

    #create_virtual_table  
  

  

    This method is for internal use only.
  



  

    

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


  



  [ GitHub ]


  

  


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



def create_virtual_table(*) # :nodoc:
end


  








  

    #database_version  
    Also known as: #postgresql_version
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 853



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


  








  

    #default_index_type?(index)  ⇒ Boolean 
  

  

    This method is for internal use only.
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 833



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


  








  

    #default_prepared_statements   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1206



def default_prepared_statements
  true
end


  








  

    #default_timezone  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 228



def default_timezone
  @default_timezone || ActiveRecord.default_timezone
end


  








  

    #default_uniqueness_comparison(attribute, value)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 805



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


  








  

    #disable_extension(name)  
  



  

    

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


  



  [ GitHub ]


  

  


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



def disable_extension(name, **)
end


  








  

    #disable_referential_integrity  
  



  

    

Override to turn off referential integrity while executing &block.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 636



def disable_referential_integrity
  yield
end


  








  

    #discard!  
  



  

    

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.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 714



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


  








  

    #disconnect!  
  



  

    

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


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 700



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


  








  

    #drop_enum  
  

  

    This method is for internal use only.
  



  

    

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


  



  [ GitHub ]


  

  


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



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


  








  

    #drop_virtual_table  
  

  

    This method is for internal use only.
  



  

    

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


  



  [ GitHub ]


  

  


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



def drop_virtual_table(*) # :nodoc:
end


  








  

    #enable_extension(name)  
  



  

    

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


  



  [ GitHub ]


  

  


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



def enable_extension(name, **)
end


  








  

    #expire  
  



  

    

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


  



  [ GitHub ]


  

  


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



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


  








  

    #extended_type_map_key   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1100



def extended_type_map_key
  if @default_timezone
    { default_timezone: @default_timezone }
  end
end


  








  

    #extensions  
  



  

    

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


  



  [ GitHub ]


  

  


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



def extensions
  []
end


  








  

    #get_advisory_lock(lock_id)  
  

  

    This method is for internal use only.
  



  

    

This is meant to be implemented by the adapters that support advisory locks



Return true if we got the lock, otherwise false


  



  [ GitHub ]


  

  


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



def get_advisory_lock(lock_id) # :nodoc:
end


  








  

    #get_database_version  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


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



def get_database_version # :nodoc:
end


  








  

    #index_algorithms  
  



  

    

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


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 629



def index_algorithms
  {}
end


  








  

    #inspect  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# 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


  








  

    #invalidate_transaction(exception)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1058



def invalidate_transaction(exception)
  return unless exception.is_a?(TransactionRollbackError)
  return unless savepoint_errors_invalidate_transactions?

  current_transaction.invalidate!
end


  








  

    #lease  
  



  

    

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


  



  [ GitHub ]


  

  


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



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


  








  

    #log(sql, name = "SQL", binds = [], type_casted_binds = [], async: false, &block)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1128



def log(sql, name = "SQL", binds = [], type_casted_binds = [], async: false, &block) # :doc:
  @instrumenter.instrument(
    "sql.active_record",
    sql:               sql,
    name:              name,
    binds:             binds,
    type_casted_binds: type_casted_binds,
    async:             async,
    connection:        self,
    transaction:       current_transaction.user_transaction.presence,
    row_count:         0,
    &block
  )
rescue ActiveRecord::StatementInvalid => ex
  raise ex.set_query(sql, binds)
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.


  





  


  [ GitHub ]


  

  


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



def prefetch_primary_key?(table_name = nil)
  false
end


  








  

    #prepared_statements?  ⇒ Boolean  (readonly)
    Also known as: #prepared_statements
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 243



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


  








  

    #prepared_statements_disabled_cache  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 248



def prepared_statements_disabled_cache # :nodoc:
  ActiveSupport::IsolatedExecutionState[:active_record_prepared_statements_disabled_cache] ||= Set.new
end


  








  

    #raw_connection  
  



  

    

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.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 797



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


  








  

    #reconnect   (private)
  



  

    
  





  
Raises:


    
  
  • 
    (NotImplementedError)
  
    • 





  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1076



def reconnect
  raise NotImplementedError
end


  








  

    #reconnect!(restore_transactions: false)  
  



  

    

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


  



  [ GitHub ]


  

  


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



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)  
  

  

    This method is for internal use only.
  



  

    

This is meant to be implemented by the adapters that support advisory locks.



Return true if we released the lock, otherwise false


  



  [ GitHub ]


  

  


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



def release_advisory_lock(lock_id) # :nodoc:
end


  








  

    #rename_enum  
  

  

    This method is for internal use only.
  



  

    

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


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 586



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


  








  

    #rename_enum_value  
  

  

    This method is for internal use only.
  



  

    

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


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 594



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


  








  

    #reset!  
  



  

    

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).


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 726



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


  








  

    #retry_deadline  
  

  [ GitHub ]


  

  


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



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


  








  

    #retryable_connection_error?(exception)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1053



def retryable_connection_error?(exception)
  (exception.is_a?(ConnectionNotEstablished) && !exception.is_a?(ConnectionNotDefined)) ||
    exception.is_a?(ConnectionFailed)
end


  








  

    #retryable_query_error?(exception)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1065



def retryable_query_error?(exception)
  # We definitely can't retry if we were inside an invalidated transaction.
  return false if current_transaction.invalidated?

  exception.is_a?(Deadlocked) || exception.is_a?(LockWaitTimeout)
end


  








  

    #return_value_after_insert?(column)  ⇒ Boolean 
  

  

    This method is for internal use only.
  



  

    
  





  


  [ GitHub ]


  

  


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



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


  








  

    #role  
  



  

    

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


  



  [ GitHub ]


  

  


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



def role
  @pool.role
end


  








  

    #schema_cache  
  

  [ GitHub ]


  

  


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



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


  








  

    #schema_version  
  



  

    

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.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 864



def schema_version
  pool.migration_context.current_version
end


  








  

    #seconds_idle  
  

  

    This method is for internal use only.
  



  

    

Seconds since this connection was returned to the pool


  



  [ GitHub ]


  

  


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



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


  








  

    #shard  
  



  

    

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


  



  [ GitHub ]


  

  


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



def shard
  @pool.shard
end


  








  

    #steal!  
  

  

    This method is for internal use only.
  



  

    

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


  



  [ GitHub ]


  

  


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



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


  








  

    #throw_away!  
  



  

    

Removes the connection from the pool and disconnect it.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 733



def throw_away!
  pool.remove self
  disconnect!
end


  








  

    #translate_exception(exception, message:, sql:, binds:)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1145



def translate_exception(exception, message:, sql:, binds:)
  # override in derived class
  case exception
  when RuntimeError, ActiveRecord::ActiveRecordError
    exception
  else
    ActiveRecord::StatementInvalid.new(message, sql: sql, binds: binds, connection_pool: @pool)
  end
end


  








  

    #translate_exception_class(native_error, sql, binds)   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1116



def translate_exception_class(native_error, sql, binds)
  return native_error if native_error.is_a?(ActiveRecordError)

  message = "#{native_error.class.name}: #{native_error.message}"

  active_record_error = translate_exception(
    native_error, message: message, sql: sql, binds: binds
  )
  active_record_error.set_backtrace(native_error.backtrace)
  active_record_error
end


  








  

    #type_map   (private)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1106



def type_map
  if key = extended_type_map_key
    self.class::EXTENDED_TYPE_MAPS.compute_if_absent(key) do
      self.class.extended_type_map(**key)
    end
  else
    self.class::TYPE_MAP
  end
end


  








  

    #unprepared_statement  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 346



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


  








  

    #valid_raw_connection   (private)
  



  

    

Similar to any_raw_connection, but ensures it is validated and connected. Any method called on this result still needs to be independently thread-safe, so it probably shouldn’t talk to the server… but some drivers fail if they know the connection has gone away.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1092



def valid_raw_connection
  (@verified && @raw_connection) ||
    # `allow_retry: false`, to force verification: the block won't
    # raise, so a retry wouldn't help us get the valid connection we
    # need.
    with_raw_connection(allow_retry: false, materialize_transactions: false) { |conn| conn }
end


  








  

    #valid_type?(type)  ⇒ Boolean 
  

  

    This method is for internal use only.
  



  

    
  





  


  [ GitHub ]


  

  


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



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


  








  

    #verified!   (private)
  



  

    

Mark the connection as verified. Call this inside a #with_raw_connection block only when the block is guaranteed to exercise the raw connection.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1049



def verified!
  @verified = true
end


  








  

    #verify!  
  



  

    

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.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 759



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


  








  

    #warning_ignored?(warning)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 1210



def warning_ignored?(warning)
  ActiveRecord.db_warnings_ignore.any? do |warning_matcher|
    warning.message.match?(warning_matcher) || warning.code.to_s.match?(warning_matcher)
  end
end


  








  

    #with_instrumenter(instrumenter, &block)  
  

  

    This method is for internal use only.
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 196



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


  








  

    #with_raw_connection(allow_retry: false, materialize_transactions: true)   (private)
  



  

    

Lock the monitor, ensure we’re properly connected and transactions are materialized, and then yield the underlying raw connection object.



If allow_retry is true, a connection-related exception will cause an automatic reconnect and re-run of the block, up to the connection’s configured #connection_retries setting and the configured #retry_deadline limit. (Note that when allow_retry is true, it’s possible to return without having marked the connection as verified. If the block is guaranteed to exercise the connection, consider calling #verified! to avoid needless verification queries in subsequent calls.)



If materialize_transactions is false, the block will be run without ensuring virtual transactions have been materialized in the DB server’s state. The active transaction will also remain clean (if it is not already dirty), meaning it’s able to be restored by reconnecting and opening an equivalent-depth set of new transactions. This should only be used by transaction control methods, and internal transaction-agnostic queries.



It’s not the primary use case, so not something to optimize for, but note that this method does need to be re-entrant: materialize_transactions will re-enter if it has work to do, and the yield block can also do so under some circumstances.



In the latter case, we really ought to guarantee the inner call will not reconnect (which would interfere with the still-yielded connection in the outer block), but we currently provide no special enforcement there.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/connection_adapters/abstract_adapter.rb', line 982



def with_raw_connection(allow_retry: false, materialize_transactions: true)
  @lock.synchronize do
    connect! if @raw_connection.nil? && reconnect_can_restore_state?

    self.materialize_transactions if materialize_transactions

    retries_available = allow_retry ? connection_retries : 0
    deadline = retry_deadline && Process.clock_gettime(Process::CLOCK_MONOTONIC) + retry_deadline
    reconnectable = reconnect_can_restore_state?

    if @verified
      # Cool, we're confident the connection's ready to use. (Note this might have
      # become true during the above #materialize_transactions.)
    elsif reconnectable
      if allow_retry
        # Not sure about the connection yet, but if anything goes wrong we can
        # just reconnect and re-run our query
      else
        # We can reconnect if needed, but we don't trust the upcoming query to be
        # safely re-runnable: let's verify the connection to be sure
        verify!
      end
    else
      # We don't know whether the connection is okay, but it also doesn't matter:
      # we wouldn't be able to reconnect anyway. We're just going to run our query
      # and hope for the best.
    end

    begin
      yield @raw_connection
    rescue => original_exception
      translated_exception = translate_exception_class(original_exception, nil, nil)
      invalidate_transaction(translated_exception)
      retry_deadline_exceeded = deadline && deadline < Process.clock_gettime(Process::CLOCK_MONOTONIC)

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

        if retryable_query_error?(translated_exception)
          backoff(connection_retries - retries_available)
          retry
        elsif reconnectable && retryable_connection_error?(translated_exception)
          reconnect!(restore_transactions: true)
          # Only allowed to reconnect once, because reconnect! has its own retry
          # loop
          reconnectable = false
          retry
        end
      end

      unless retryable_query_error?(translated_exception)
        # Barring a known-retryable error inside the query (regardless of
        # whether we were in a _position_ to retry it), we should infer that
        # there's likely a real problem with the connection.
        @verified = false
      end

      raise translated_exception
    ensure
      dirty_current_transaction if materialize_transactions
    end
  end
end