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class ActiveRecord::ConnectionAdapters::MysqlAdapter

Parent:: ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter

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.

Constants

ADAPTER_NAME

ENCODINGS

Taken from here:

https://github.com/tmtm/ruby-mysql/blob/master/lib/mysql/charset.rb

Author: TOMITA Masahiro <[email protected]>

Public Class Methods

new(connection, logger, connection_options, config) Show source

Calls superclass method ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter.new

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 132
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

Public Instance Methods

active?() Show source

CONNECTION MANAGEMENT ====================================

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 175
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

clear_cache!() Show source

Clears the prepared statements cache.

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 224
def clear_cache!
  @statements.clear
end

client_encoding() Show source

Get the client encoding for this database

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 272
def client_encoding
  return @client_encoding if @client_encoding

  result = exec_query(
    "SHOW VARIABLES WHERE Variable_name = 'character_set_client'",
    'SCHEMA')
  @client_encoding = ENCODINGS[result.rows.last.last]
end

disconnect!() Show source

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

Calls superclass method ActiveRecord::ConnectionAdapters::AbstractAdapter#disconnect!

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 200
def disconnect!
  super
  @connection.close rescue nil
end

exec_delete(sql, name, binds) Show source

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 463
def exec_delete(sql, name, binds)
  affected_rows = 0

  exec_query(sql, name, binds) do |n|
    affected_rows = n
  end

  affected_rows
end

Also aliased as: exec_update

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

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 281
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

execute_and_free(sql, name = nil) { |result| ... } Show source

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 450
def execute_and_free(sql, name = nil)
  result = execute(sql, name)
  ret = yield result
  result.free
  ret
end

last_inserted_id(result) Show source

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 293
def last_inserted_id(result)
  @connection.insert_id
end

reconnect!() Show source

Calls superclass method ActiveRecord::ConnectionAdapters::AbstractAdapter#reconnect!

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 192
def reconnect!
  super
  disconnect!
  connect
end

reset!() Show source

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 205
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 = []) Show source

DATABASE STATEMENTS ======================================

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

supports_statement_cache?() Show source

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

# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 142
def supports_statement_cache?
  true
end