Class: ActiveRecord::ConnectionAdapters::Mysql2Adapter

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, `AbstractMysqlAdapter`, `AbstractAdapter`, `::ActiveSupport::DescendantsTracker`
Instance Chain: self, `Mysql2::DatabaseStatements`, `AbstractMysqlAdapter`, `MySQL::DatabaseStatements`, `AbstractAdapter`, `Savepoints`, `::ActiveRecord::QueryCache`, `DatabaseLimits`, `Quoting`, `DatabaseStatements`, `SchemaStatements`, `::ActiveSupport::Callbacks`
Inherits:	ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter `::Object` ActiveRecord::ConnectionAdapters::AbstractAdapter ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter ActiveRecord::ConnectionAdapters::Mysql2Adapter
Defined in:	activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb

Overview

Active Record MySQL2 Adapter

Constant Summary

ADAPTER_NAME =
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 19
```
"Mysql2"
```
ER_ACCESS_DENIED_ERROR =
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 15
```
1045
```
ER_BAD_DB_ERROR =
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 13
```
1049
```
ER_CONN_HOST_ERROR =
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 16
```
2003
```
ER_DBACCESS_DENIED_ERROR =
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 14
```
1044
```
ER_UNKNOWN_HOST_ERROR =
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 17
```
2005
```
TYPE_MAP =
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 53
```
Type::TypeMap.new.tap { |m| initialize_type_map(m) }
```

`::ActiveSupport::Callbacks` - Included

CALLBACK_FILTER_TYPES

`DatabaseStatements` - Included

DEFAULT_INSERT_VALUE

`AbstractAdapter` - Inherited

ADAPTER_NAME, COMMENT_REGEX, EXTENDED_TYPE_MAPS, SIMPLE_INT, TYPE_MAP

`AbstractMysqlAdapter` - Inherited

CR_SERVER_GONE_ERROR, CR_SERVER_LOST, EMULATE_BOOLEANS_TRUE, ER_CANNOT_ADD_FOREIGN, ER_CANNOT_CREATE_TABLE, ER_CLIENT_INTERACTION_TIMEOUT, ER_CONNECTION_KILLED, ER_DATA_TOO_LONG, ER_DB_CREATE_EXISTS, ER_DO_NOT_HAVE_DEFAULT, ER_DUP_ENTRY, ER_FILSORT_ABORT, ER_FK_INCOMPATIBLE_COLUMNS, ER_LOCK_DEADLOCK, ER_LOCK_WAIT_TIMEOUT, ER_NOT_NULL_VIOLATION, ER_NO_REFERENCED_ROW, ER_NO_REFERENCED_ROW_2, ER_OUT_OF_RANGE, ER_QUERY_INTERRUPTED, ER_QUERY_TIMEOUT, ER_ROW_IS_REFERENCED, ER_ROW_IS_REFERENCED_2, ER_SERVER_SHUTDOWN, EXTENDED_TYPE_MAPS, NATIVE_DATABASE_TYPES

Class Attribute Summary

`AbstractMysqlAdapter` - Inherited

.emulate_booleans, .emulate_booleans?

`AbstractAdapter` - Inherited

.__callbacks

`AbstractMysqlAdapter` - Inherited

.dbconsole

`AbstractAdapter` - Inherited

.database_exists?	Does the database for this adapter exist?
.dbconsole	Opens a database console session.
.find_cmd_and_exec, .type_cast_config_to_boolean, .type_cast_config_to_integer, .validate_default_timezone

`::ActiveSupport::DescendantsTracker` - Inherited

descendants, subclasses

Instance Attribute Summary

#active? ⇒ Boolean readonly
#connected? ⇒ Boolean readonly
#savepoint_errors_invalidate_transactions? ⇒ Boolean readonly
#supports_comments? ⇒ Boolean readonly
#supports_comments_in_create? ⇒ Boolean readonly
#supports_json? ⇒ Boolean readonly
#supports_lazy_transactions? ⇒ Boolean readonly
#supports_savepoints? ⇒ Boolean readonly

`AbstractMysqlAdapter` - Inherited

#emulate_booleans, #emulate_booleans?, #strict_mode?, #supports_advisory_locks?, #supports_bulk_alter?, #supports_check_constraints?, #supports_common_table_expressions?, #supports_datetime_with_precision?, #supports_explain?, #supports_expression_index?, #supports_foreign_keys?, #supports_index_sort_order?, #supports_indexes_in_create?, #supports_insert_on_duplicate_skip?, #supports_insert_on_duplicate_update?, #supports_insert_returning?,
#supports_optimizer_hints?	See dev.mysql.com/doc/refman/en/optimizer-hints.html for more details.
#supports_restart_db_transaction?, #supports_transaction_isolation?, #supports_views?, #supports_virtual_columns?

`AbstractAdapter` - Inherited

#__callbacks,
#active?	Checks whether the connection to the database is still active.
#connected?	Checks whether the connection to the database was established.
#database_exists?,
#in_use?	Alias for AbstractAdapter#owner.
#lock, #logger, #owner, #pool, #pool=,
#prepared_statements	Alias for AbstractAdapter#prepared_statements?.
#preventing_writes?	Determines whether writes are currently being prevented.
#replica?,
#requires_reloading?	Returns true if its required to reload the connection between requests for development mode.
#savepoint_errors_invalidate_transactions?	Do TransactionRollbackErrors on savepoints affect the parent transaction?
#supports_advisory_locks?	Does this adapter support application-enforced advisory locking?
#supports_bulk_alter?,
#supports_check_constraints?	Does this adapter support creating check constraints?
#supports_comments?	Does this adapter support metadata comments on database objects (tables, columns, indexes)?
#supports_comments_in_create?	Can comments for tables, columns, and indexes be specified in create/alter table statements?
#supports_common_table_expressions?, #supports_concurrent_connections?,
#supports_datetime_with_precision?	Does this adapter support datetime with precision?
#supports_ddl_transactions?	Does this adapter support DDL rollbacks in transactions? That is, would CREATE TABLE or ALTER TABLE get rolled back by a transaction?
#supports_deferrable_constraints?	Does this adapter support creating deferrable constraints?
#supports_exclusion_constraints?	Does this adapter support creating exclusion constraints?
#supports_explain?	Does this adapter support explain?
#supports_expression_index?	Does this adapter support expression indices?
#supports_extensions?	Does this adapter support database extensions?
#supports_foreign_keys?	Does this adapter support creating foreign key constraints?
#supports_foreign_tables?	Does this adapter support foreign/external tables?
#supports_index_include?	Does this adapter support including non-key columns?
#supports_index_sort_order?	Does this adapter support index sort order?
#supports_indexes_in_create?	Does this adapter support creating indexes in the same statement as creating the table?
#supports_insert_conflict_target?, #supports_insert_on_duplicate_skip?, #supports_insert_on_duplicate_update?, #supports_insert_returning?,
#supports_json?	Does this adapter support JSON data type?
#supports_lazy_transactions?,
#supports_materialized_views?	Does this adapter support materialized views?
#supports_nulls_not_distinct?,
#supports_optimizer_hints?	Does this adapter support optimizer hints?
#supports_partial_index?	Does this adapter support partial indices?
#supports_partitioned_indexes?, #supports_restart_db_transaction?,
#supports_savepoints?	Does this adapter support savepoints?
#supports_transaction_isolation?	Does this adapter support setting the isolation level for a transaction?
#supports_unique_constraints?	Does this adapter support creating unique constraints?
#supports_validate_constraints?	Does this adapter support creating invalid constraints?
#supports_views?	Does this adapter support views?
#supports_virtual_columns?	Does this adapter support virtual columns?
#visitor

`DatabaseStatements` - Included

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

`SchemaStatements` - Included

#use_foreign_keys?

Instance Method Summary

#disconnect!

Disconnects from the database if already connected.
#error_number(exception)

HELPER METHODS ===========================================.
#reset!

`AbstractMysqlAdapter` - Inherited

#charset	Returns the database character set.
#check_constraints,
#collation	Returns the database collation strategy.
#create_database	Create a new `MySQL` database with optional `:charset` and `:collation`.
#current_database,
#drop_table	Drops a table or tables from the database.
#foreign_keys, #index_algorithms, #native_database_types,
#quote_string	Quotes strings for use in SQL input.
#recreate_database	Drops the database specified on the `name` attribute and creates it again using the provided `options`.
#rename_index,
#rename_table	Renames a table.
#show_variable	SHOW VARIABLES LIKE ‘name’.

`MySQL::DatabaseStatements` - Included

#build_explain_clause, #explain, #high_precision_current_timestamp

`AbstractAdapter` - Inherited

#adapter_name	Returns the human-readable name of the adapter.
#check_all_foreign_keys_valid!	Override to check all foreign key constraints in a database.
#clear_cache!	Clear any caching the database adapter may be doing.
#close	Check the connection back in to the connection pool.
#connect!, #connection_retries, #default_timezone,
#disable_extension	This is meant to be implemented by the adapters that support extensions.
#disable_referential_integrity	Override to turn off referential integrity while executing `&block`.
#discard!	Immediately forget this connection ever existed.
#disconnect!	Disconnects from the database if already connected.
#enable_extension	This is meant to be implemented by the adapters that support extensions.
#expire	this method must only be called while holding connection pool’s mutex.
#extensions	A list of extensions, to be filled in by adapters that support them.
#index_algorithms	A list of index algorithms, to be filled by adapters that support them.
#lease	this method must only be called while holding connection pool’s mutex.
#prefetch_primary_key?	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.
#prepared_statements?,
#raw_connection	Provides access to the underlying database driver for this adapter.
#reconnect!	Disconnects from the database if already connected, and establishes a new connection with the database.
#reset!	Reset the state of this connection, directing the DBMS to clear transactions and other connection-related server-side state.
#retry_deadline,
#role	The role (e.g. `:writing`) for the current connection.
#schema_cache,
#schema_version	Returns the version identifier of the schema currently available in the database.
#shard	The shard (e.g. `:default`) for the current connection.
#throw_away!	Removes the connection from the pool and disconnect it.
#unprepared_statement,
#verify!	Checks whether the connection to the database is still active (i.e. not stale).
#log

`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.

`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

`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.

`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.

`::ActiveSupport::Callbacks` - Included

#run_callbacks

Runs the callbacks for the given event.

Constructor Details

.new ⇒ `Mysql2Adapter`

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 55


def initialize(...)
  super

  @affected_rows_before_warnings = nil
  @config[:flags] ||= 0

  if @config[:flags].kind_of? Array
    @config[:flags].push "FOUND_ROWS"
  else
    @config[:flags] |= ::Mysql2::Client::FOUND_ROWS
  end

  @connection_parameters ||= @config
end

Class Method Details

.new_client(config)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 24


def new_client(config)
  ::Mysql2::Client.new(config)
rescue ::Mysql2::Error => error
  case error.error_number
  when ER_BAD_DB_ERROR
    raise ActiveRecord::NoDatabaseError.db_error(config[:database])
  when ER_DBACCESS_DENIED_ERROR, ER_ACCESS_DENIED_ERROR
    raise ActiveRecord::DatabaseConnectionError.username_error(config[:username])
  when ER_CONN_HOST_ERROR, ER_UNKNOWN_HOST_ERROR
    raise ActiveRecord::DatabaseConnectionError.hostname_error(config[:host])
  else
    raise ActiveRecord::ConnectionNotEstablished, error.message
  end
end

Instance Attribute Details

#active? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 108


def active?
  connected? && @lock.synchronize { @raw_connection&.ping } || false
end

#connected? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 104


def connected?
  !(@raw_connection.nil? || @raw_connection.closed?)
end

#savepoint_errors_invalidate_transactions? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 86


def savepoint_errors_invalidate_transactions?
  true
end

#supports_comments? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 74


def supports_comments?
  true
end

#supports_comments_in_create? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 78


def supports_comments_in_create?
  true
end

#supports_json? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 70


def supports_json?
  !mariadb? && database_version >= "5.7.8"
end

#supports_lazy_transactions? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 90


def supports_lazy_transactions?
  true
end

#supports_savepoints? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 82


def supports_savepoints?
  true
end

Instance Method Details

#disconnect!

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 116


def disconnect!
  @lock.synchronize do
    super
    @raw_connection&.close
    @raw_connection = nil
  end
end

#error_number(exception)

HELPER METHODS ===========================================

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 96


def error_number(exception)
  exception.error_number if exception.respond_to?(:error_number)
end

#reset!

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 112


alias :reset! :reconnect!

Class: ActiveRecord::ConnectionAdapters::Mysql2Adapter

Overview

Active Record MySQL2 Adapter

Constant Summary

::ActiveSupport::Callbacks - Included

DatabaseStatements - Included

AbstractAdapter - Inherited

AbstractMysqlAdapter - Inherited

Class Attribute Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

Class Method Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

::ActiveSupport::DescendantsTracker - Inherited

Instance Attribute Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

DatabaseStatements - Included

SchemaStatements - Included

Instance Method Summary

AbstractMysqlAdapter - Inherited

MySQL::DatabaseStatements - Included

AbstractAdapter - Inherited

Savepoints - Included

DatabaseLimits - Included

Quoting - Included

DatabaseStatements - Included

SchemaStatements - Included

::ActiveSupport::Callbacks - Included

Constructor Details

.new ⇒ Mysql2Adapter

Class Method Details

.new_client(config)

Instance Attribute Details

#active? ⇒ Boolean (readonly)

#connected? ⇒ Boolean (readonly)

#savepoint_errors_invalidate_transactions? ⇒ Boolean (readonly)

#supports_comments? ⇒ Boolean (readonly)

#supports_comments_in_create? ⇒ Boolean (readonly)

#supports_json? ⇒ Boolean (readonly)

#supports_lazy_transactions? ⇒ Boolean (readonly)

#supports_savepoints? ⇒ Boolean (readonly)

Instance Method Details

#disconnect!

#error_number(exception)

#reset!

`::ActiveSupport::Callbacks` - Included

`DatabaseStatements` - Included

`AbstractAdapter` - Inherited

`AbstractMysqlAdapter` - Inherited

`AbstractMysqlAdapter` - Inherited

`AbstractAdapter` - Inherited

`AbstractMysqlAdapter` - Inherited

`AbstractAdapter` - Inherited

`::ActiveSupport::DescendantsTracker` - Inherited

`AbstractMysqlAdapter` - Inherited

`AbstractAdapter` - Inherited

`DatabaseStatements` - Included

`SchemaStatements` - Included

`AbstractMysqlAdapter` - Inherited

`MySQL::DatabaseStatements` - Included

`AbstractAdapter` - Inherited

`Savepoints` - Included

`DatabaseLimits` - Included

`Quoting` - Included

`DatabaseStatements` - Included

`SchemaStatements` - Included

`::ActiveSupport::Callbacks` - Included

.new ⇒ `Mysql2Adapter`

#active? ⇒ `Boolean` (readonly)

#connected? ⇒ `Boolean` (readonly)

#savepoint_errors_invalidate_transactions? ⇒ `Boolean` (readonly)

#supports_comments? ⇒ `Boolean` (readonly)

#supports_comments_in_create? ⇒ `Boolean` (readonly)

#supports_json? ⇒ `Boolean` (readonly)

#supports_lazy_transactions? ⇒ `Boolean` (readonly)

#supports_savepoints? ⇒ `Boolean` (readonly)