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Class: ActiveRecord::ConnectionAdapters::Mysql2Adapter

Overview

Active Record MySQL2 Adapter

Constant Summary

::ActiveSupport::Callbacks - Included

CALLBACK_FILTER_TYPES

DatabaseStatements - Included

DEFAULT_INSERT_VALUE

Quoting - Included

COLUMN_NAME, COLUMN_NAME_WITH_ORDER

AbstractAdapter - Inherited

ADAPTER_NAME, COMMENT_REGEX, EXTENDED_TYPE_MAPS, FIBER_LOCK, SIMPLE_INT, THREAD_LOCK, 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, EXTENDED_TYPE_MAPS, NATIVE_DATABASE_TYPES

Class Attribute Summary

Class Method Summary

AbstractMysqlAdapter - Inherited

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

See additional method definition at line 104.

subclasses

See additional method definition at line 100.

Instance Attribute Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

#__callbacks, #__callbacks?,
#active?

Checks whether the connection to the database is still active.

#all_foreign_keys_valid?

Override to check all foreign key constraints in a database.

#database_exists?,
#in_use?
#lock, #logger, #owner, #pool, #pool=,
#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?

#use_metadata_table?, #visitor

DatabaseStatements - Included

SchemaStatements - Included

Instance Method Summary

Mysql2::DatabaseStatements - Included

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 from the database.

#foreign_keys, #index_algorithms, #native_database_types,
#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

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

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_bound_value

Quote a value to be used as a bound parameter of unknown type.

#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
#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_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
#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 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
#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

.newMysql2Adapter

[ GitHub ]

  
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 66

def initialize(...)
  super

  @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 35

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 133

def active?
  !(@raw_connection.nil? || @raw_connection.closed?) && @lock.synchronize { @raw_connection&.ping } || false
end

#savepoint_errors_invalidate_transactions?Boolean (readonly)

[ GitHub ]

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

def savepoint_errors_invalidate_transactions?
  true
end

#supports_comments?Boolean (readonly)

[ GitHub ]

  
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 84

def supports_comments?
  true
end

#supports_comments_in_create?Boolean (readonly)

[ GitHub ]

  
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 88

def supports_comments_in_create?
  true
end

#supports_json?Boolean (readonly)

[ GitHub ]

  
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 80

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 100

def supports_lazy_transactions?
  true
end

#supports_savepoints?Boolean (readonly)

[ GitHub ]

  
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 92

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 141

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

#error_number(exception)

[ GitHub ]

  
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 114

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

#quote_string(string)

Quotes strings for use in SQL input.

[ GitHub ]

  
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 123

def quote_string(string)
  with_raw_connection(allow_retry: true, materialize_transactions: false) do |connection|
    connection.escape(string)
  end
end

#reset!

[ GitHub ]

  
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 137

alias :reset! :reconnect!