Class: ActiveRecord::ConnectionAdapters::MysqlAdapter

Relationships & Source Files
Namespace Children
Classes: StatementPool
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, AbstractMysqlAdapter, AbstractAdapter, ::ActiveSupport::DescendantsTracker
Instance Chain: self, AbstractMysqlAdapter, AbstractAdapter, ColumnDumper, MonitorMixin, ::ActiveSupport::Callbacks, ::ActiveRecord::QueryCache, DatabaseLimits, Quoting, DatabaseStatements, SchemaStatements
Inherits:	ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter ::Object ActiveRecord::ConnectionAdapters::AbstractAdapter ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter ActiveRecord::ConnectionAdapters::MysqlAdapter
Defined in:	activerecord/lib/active_record/connection_adapters/mysql_adapter.rb

Overview

The MySQL adapter will work with both Ruby/MySQL, which is a Ruby-based MySQL adapter that comes bundled with Active Record, and with the faster C-based MySQL/Ruby adapter (available both as a gem and from www.tmtm.org/en/mysql/ruby/).

Options:

:host - Defaults to “localhost”.
:port - Defaults to 3306.
:socket - Defaults to “/tmp/mysql.sock”.
:username - Defaults to “root”
:password - Defaults to nothing.
:database - The name of the database. No default, must be provided.
:encoding - (Optional) Sets the client encoding by executing “SET NAMES <encoding>” after connection.
:reconnect - Defaults to false (See MySQL documentation: dev.mysql.com/doc/refman/5.0/en/auto-reconnect.html).
:strict - Defaults to true. Enable STRICT_ALL_TABLES. (See MySQL documentation: dev.mysql.com/doc/refman/5.0/en/sql-mode.html)
:variables - (Optional) A hash session variables to send as SET @@SESSION.key = value on each database connection. Use the value :default to set a variable to its DEFAULT value. (See MySQL documentation: dev.mysql.com/doc/refman/5.0/en/set-statement.html).
:sslca - Necessary to use MySQL with an SSL connection.
:sslkey - Necessary to use MySQL with an SSL connection.
:sslcert - Necessary to use MySQL with an SSL connection.
:sslcapath - Necessary to use MySQL with an SSL connection.
:sslcipher - Necessary to use MySQL with an SSL connection.

Constant Summary

ADAPTER_NAME =
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 69
```
'MySQL'.freeze
```

ENCODINGS =

Taken from here: github.com/tmtm/ruby-mysql/blob/master/lib/mysql/charset.rb Author: TOMITA Masahiro <tommy@tmtm.org>

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

{
  "armscii8" => nil,
  "ascii"    => Encoding::US_ASCII,
  "big5"     => Encoding::Big5,
  "binary"   => Encoding::ASCII_8BIT,
  "cp1250"   => Encoding::Windows_1250,
  "cp1251"   => Encoding::Windows_1251,
  "cp1256"   => Encoding::Windows_1256,
  "cp1257"   => Encoding::Windows_1257,
  "cp850"    => Encoding::CP850,
  "cp852"    => Encoding::CP852,
  "cp866"    => Encoding::IBM866,
  "cp932"    => Encoding::Windows_31J,
  "dec8"     => nil,
  "eucjpms"  => Encoding::EucJP_ms,
  "euckr"    => Encoding::EUC_KR,
  "gb2312"   => Encoding::EUC_CN,
  "gbk"      => Encoding::GBK,
  "geostd8"  => nil,
  "greek"    => Encoding::ISO_8859_7,
  "hebrew"   => Encoding::ISO_8859_8,
  "hp8"      => nil,
  "keybcs2"  => nil,
  "koi8r"    => Encoding::KOI8_R,
  "koi8u"    => Encoding::KOI8_U,
  "latin1"   => Encoding::ISO_8859_1,
  "latin2"   => Encoding::ISO_8859_2,
  "latin5"   => Encoding::ISO_8859_9,
  "latin7"   => Encoding::ISO_8859_13,
  "macce"    => Encoding::MacCentEuro,
  "macroman" => Encoding::MacRoman,
  "sjis"     => Encoding::SHIFT_JIS,
  "swe7"     => nil,
  "tis620"   => Encoding::TIS_620,
  "ucs2"     => Encoding::UTF_16BE,
  "ujis"     => Encoding::EucJP_ms,
  "utf8"     => Encoding::UTF_8,
  "utf8mb4"  => Encoding::UTF_8,
}

Class Attribute Summary

AbstractMysqlAdapter - Inherited

.emulate_booleans, .emulate_booleans?

Class Method Summary

.new(connection, logger, connection_options, config) ⇒ MysqlAdapter constructor

AbstractMysqlAdapter - Inherited

.new	FIXME: Make the first parameter more similar for the two adapters.

AbstractAdapter - Inherited

.type_cast_config_to_boolean, .type_cast_config_to_integer

::ActiveSupport::DescendantsTracker - Inherited

clear, descendants, direct_descendants,
store_inherited	This is the only method that is not thread safe, but is only ever called during the eager loading phase.

Instance Attribute Summary

#active? ⇒ Boolean readonly
#supports_statement_cache? ⇒ Boolean readonly

Returns true, since this connection adapter supports prepared statement caching.

AbstractMysqlAdapter - Inherited

#emulate_booleans, #emulate_booleans?, #strict_mode?, #supports_datetime_with_precision?, #supports_foreign_keys?,
#supports_index_sort_order?	Technically MySQL allows to create indexes with the sort order syntax but at the moment (5.5) it doesn't yet implement them.
#supports_indexes_in_create?,
#supports_migrations?	Returns true, since this connection adapter supports migrations.
#supports_primary_key?,
#supports_transaction_isolation?	MySQL 4 technically support transaction isolation, but it is affected by a bug where the transaction level gets persisted for the whole session:
#supports_views?

AbstractAdapter - Inherited

#active?	Checks whether the connection to the database is still active.
#in_use?	Alias for AbstractAdapter#owner.
#logger, #owner, #pool, #prepared_statements,
#requires_reloading?	Returns true if its required to reload the connection between requests for development mode.
#schema_cache, #schema_cache=, #supports_bulk_alter?,
#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_explain?	Does this adapter support explain?
#supports_extensions?	Does this adapter support database extensions?
#supports_foreign_keys?	Does this adapter support creating foreign key constraints?
#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_migrations?	Does this adapter support migrations?
#supports_partial_index?	Does this adapter support partial indices?
#supports_primary_key?	Can this adapter determine the primary key for tables not attached to an Active Record class, such as join tables?
#supports_savepoints?	Does this adapter support savepoints?
#supports_transaction_isolation?	Does this adapter support setting the isolation level for a transaction?
#supports_views?	Does this adapter support views?
#visitor

DatabaseStatements - Included

#begin_transaction, #commit_transaction, #current_transaction, #open_transactions, #rollback_transaction,
#supports_statement_cache?	Returns `true` when the connection adapter supports prepared statement caching, otherwise returns `false`
#transaction_open?, #within_new_transaction

Instance Method Summary

#clear_cache!

Clears the prepared statements cache.
#client_encoding

Get the client encoding for this database.
#create(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

Alias for #insert_sql.
#disconnect!

Disconnects from the database if already connected.
#exec_query(sql, name = 'SQL', binds = []) {|affected_rows| ... }
#exec_update(sql, name, binds)

Alias for #exec_delete.
#last_inserted_id(result)
#reconnect!
#reset!
#select_rows(sql, name = nil, binds = [])

AbstractMysqlAdapter - Inherited

#begin_db_transaction, #begin_isolated_db_transaction, #case_insensitive_comparison, #case_sensitive_comparison, #case_sensitive_modifier, #change_column_null,
#charset	Returns the database character set.
#clear_cache!,
#collation	Returns the database collation strategy.
#create_database	Create a new MySQL database with optional `:charset` and `:collation`.
#current_database,
#data_source_exists?	Alias for AbstractMysqlAdapter#table_exists?.
#data_sources	Alias for AbstractMysqlAdapter#tables.
#drop_table, #empty_insert_statement_value,
#execute	Executes the SQL statement in the context of this connection.
#foreign_keys, #index_algorithms, #native_database_types,
#pk_and_sequence_for	Returns a table's primary key and belonging sequence.
#primary_key	Returns just a table's primary key.
#quoted_date, #quoted_false, #quoted_true,
#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.
#schema_creation,
#show_variable	SHOW VARIABLES LIKE 'name'.
#table_exists?, #truncate,
#type_to_sql	Maps logical ::Rails types to MySQL-specific data types.
#unquoted_false, #unquoted_true, #valid_type?

AbstractAdapter - Inherited

#adapter_name	Returns the human-readable name of the adapter.
#case_insensitive_comparison, #case_sensitive_comparison, #case_sensitive_modifier,
#clear_cache!	Clear any caching the database adapter may be doing, for example clearing the prepared statement cache.
#close	Check the connection back in to the connection pool.
#collector, #create_savepoint, #current_savepoint_name,
#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`.
#disconnect!	Disconnects from the database if already connected.
#enable_extension	This is meant to be implemented by the adapters that support extensions.
#expire,
#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, #new_column,
#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.
#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.
#release_savepoint,
#reset!	Reset the state of this connection, directing the DBMS to clear transactions and other connection-related server-side state.
#schema_creation,
#substitute_at	Returns a bind substitution value given a bind `column` NOTE: The column param is currently being used by the sqlserver-adapter.
#unprepared_statement, #valid_type?,
#verify!	Checks whether the connection to the database is still active (i.e. not stale).

ColumnDumper - Included

#column_spec,
#migration_keys	Lists the valid migration options.
#prepare_column_options	This can be overridden on a Adapter level basis to support other extended datatypes (Example: Adding an array option in the PostgreSQLAdapter).

::ActiveSupport::Callbacks - Included

#run_callbacks

Runs the callbacks for the given event.

::ActiveRecord::QueryCache - Included

#call

DatabaseLimits - Included

#allowed_index_name_length	Returns the maximum allowed length for an index name.
#column_name_length	Returns the maximum length of a column name.
#columns_per_multicolumn_index	Returns the maximum number of columns in a multicolumn index.
#columns_per_table	Returns the maximum number of columns per table.
#in_clause_length	Returns the maximum number of elements in an IN (x,y,z) clause.
#index_name_length	Returns the maximum length of an index name.
#indexes_per_table	Returns the maximum number of indexes per table.
#joins_per_query	Returns maximum number of joins in a single query.
#sql_query_length	Returns the maximum length of an SQL query.
#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, #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).
#default_sequence_name,
#delete	Executes the delete statement and returns the number of rows affected.
#empty_insert_statement_value,
#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.
#initialize,
#insert	Returns the last auto-generated ID from the affected table.
#insert_fixture	Inserts the given fixture into the table.
#reset_sequence!	Set the sequence to the max value of the table's column.
#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, #transaction_state,
#truncate	Executes the truncate statement.
#update	Executes the update statement and returns the number of rows affected.

SchemaStatements - Included

#add_belongs_to	Alias for SchemaStatements#add_reference.
#add_column	Adds a new column to the named table.
#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,
#change_column	Changes the column's definition according to the new options.
#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`.
#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 useable 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_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.
#initialize_schema_migrations_table	Should not be called normally, but this operation is non-destructive.
#native_database_types	Returns a hash of mappings from the abstract data types to the native database types.
#remove_belongs_to	Alias for SchemaStatements#remove_reference.
#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_exists?	Checks to see if the table `table_name` exists on the database.

Constructor Details

.new(connection, logger, connection_options, config) ⇒ `MysqlAdapter`

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 103


def initialize(connection, logger, connection_options, config)
  super
  @statements = StatementPool.new(@connection,
                                  self.class.type_cast_config_to_integer(config.fetch(:statement_limit) { 1000 }))
  @client_encoding = nil
  connect
end

Instance Attribute Details

#active? ⇒ `Boolean` (readonly)

[ GitHub ]

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


def active?
  if @connection.respond_to?(:stat)
    @connection.stat
  else
    @connection.query 'select 1'
  end

  # mysql-ruby doesn't raise an exception when stat fails.
  if @connection.respond_to?(:errno)
    @connection.errno.zero?
  else
    true
  end
rescue Mysql::Error
  false
end

#supports_statement_cache? ⇒ `Boolean` (readonly)

Returns true, since this connection adapter supports prepared statement caching.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 113


def supports_statement_cache?
  true
end

Instance Method Details

#clear_cache!

Clears the prepared statements cache.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 195


def clear_cache!
  super
  @statements.clear
end

#client_encoding

Get the client encoding for this database

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 244


def client_encoding
  return @client_encoding if @client_encoding

  result = exec_query(
    "select @@character_set_client",
    'SCHEMA')
  @client_encoding = ENCODINGS[result.rows.last.last]
end

#create(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

Alias for #insert_sql.

[ GitHub ]

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


alias :create :insert_sql

#disconnect!

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 169


def disconnect!
  super
  @connection.close rescue nil
end

#exec_query(sql, name = 'SQL', binds = []) {|affected_rows| ... }

Yields:

(affected_rows)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 253


def exec_query(sql, name = 'SQL', binds = [])
  if without_prepared_statement?(binds)
    result_set, affected_rows = exec_without_stmt(sql, name)
  else
    result_set, affected_rows = exec_stmt(sql, name, binds)
  end

  yield affected_rows if block_given?

  result_set
end

#exec_update(sql, name, binds)

Alias for #exec_delete.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 395


alias :exec_update :exec_delete

#last_inserted_id(result)

[ GitHub ]

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


def last_inserted_id(result)
  @connection.insert_id
end

#reconnect!

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 161


def reconnect!
  super
  disconnect!
  connect
end

#reset!

[ GitHub ]

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


def reset!
  if @connection.respond_to?(:change_user)
    # See http://bugs.mysql.com/bug.php?id=33540 -- the workaround way to
    # reset the connection is to change the user to the same user.
    @connection.change_user(@config[:username], @config[:password], @config[:database])
    configure_connection
  end
end

#select_rows(sql, name = nil, binds = [])

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 187


def select_rows(sql, name = nil, binds = [])
  @connection.query_with_result = true
  rows = exec_query(sql, name, binds).rows
  @connection.more_results && @connection.next_result    # invoking stored procedures with CLIENT_MULTI_RESULTS requires this to tidy up else connection will be dropped
  rows
end

Class: ActiveRecord::ConnectionAdapters::MysqlAdapter

Overview

Constant Summary

::ActiveSupport::Callbacks - Included

AbstractAdapter - Inherited

AbstractMysqlAdapter - Inherited

Class Attribute Summary

AbstractMysqlAdapter - Inherited

Class Method Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

::ActiveSupport::DescendantsTracker - Inherited

Instance Attribute Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

DatabaseStatements - Included

Instance Method Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

ColumnDumper - Included

::ActiveSupport::Callbacks - Included

::ActiveRecord::QueryCache - Included

DatabaseLimits - Included

Quoting - Included

DatabaseStatements - Included

SchemaStatements - Included

Constructor Details

.new(connection, logger, connection_options, config) ⇒ MysqlAdapter

Instance Attribute Details

#active? ⇒ Boolean (readonly)

#supports_statement_cache? ⇒ Boolean (readonly)

Instance Method Details

#clear_cache!

#client_encoding

#create(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

#disconnect!

#exec_query(sql, name = 'SQL', binds = []) {|affected_rows| ... }

#exec_update(sql, name, binds)

#last_inserted_id(result)

#reconnect!

#reset!

#select_rows(sql, name = nil, binds = [])

.new(connection, logger, connection_options, config) ⇒ `MysqlAdapter`

#active? ⇒ `Boolean` (readonly)

#supports_statement_cache? ⇒ `Boolean` (readonly)