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).
  • :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.
Methods
Constants
ADAPTER_NAME = 'MySQL'.freeze
LOST_CONNECTION_ERROR_MESSAGES = [ "Server shutdown in progress", "Broken pipe", "Lost connection to MySQL server during query", "MySQL server has gone away" ]
QUOTED_FALSE = '1'.freeze, '0'.freeze
NATIVE_DATABASE_TYPES = { :primary_key => "int(11) DEFAULT NULL auto_increment PRIMARY KEY".freeze, :string => { :name => "varchar", :limit => 255 }, :text => { :name => "text" }, :integer => { :name => "int", :limit => 4 }, :float => { :name => "float" }, :decimal => { :name => "decimal" }, :datetime => { :name => "datetime" }, :timestamp => { :name => "datetime" }, :time => { :name => "time" }, :date => { :name => "date" }, :binary => { :name => "blob" }, :boolean => { :name => "tinyint", :limit => 1 }
Public Class methods
new(connection, logger, connection_options, config)

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 202
202:       def initialize(connection, logger, connection_options, config)
203:         super(connection, logger)
204:         @connection_options, @config = connection_options, config
205:         @quoted_column_names, @quoted_table_names = {}, {}
206:         connect
207:       end
Public Instance methods
active?()

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

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 274
274:       def active?
275:         if @connection.respond_to?(:stat)
276:           @connection.stat
277:         else
278:           @connection.query 'select 1'
279:         end
280: 
281:         # mysql-ruby doesn't raise an exception when stat fails.
282:         if @connection.respond_to?(:errno)
283:           @connection.errno.zero?
284:         else
285:           true
286:         end
287:       rescue Mysql::Error
288:         false
289:       end
case_sensitive_equality_operator()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 559
559:       def case_sensitive_equality_operator
560:         "= BINARY"
561:       end
change_column_null(table_name, column_name, null, default = nil)

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 487
487:       def change_column_null(table_name, column_name, null, default = nil)
488:         column = column_for(table_name, column_name)
489: 
490:         unless null || default.nil?
491:           execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
492:         end
493: 
494:         change_column table_name, column_name, column.sql_type, :null => null
495:       end
charset()

Returns the database character set.

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 427
427:       def charset
428:         show_variable 'character_set_database'
429:       end
collation()

Returns the database collation strategy.

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 432
432:       def collation
433:         show_variable 'collation_database'
434:       end
create_database(name, options = {})

Create a new MySQL database with optional :charset and :collation. Charset defaults to utf8.

Example: 

  create_database 'charset_test', :charset => 'latin1', :collation => 'latin1_bin'
  create_database 'matt_development'
  create_database 'matt_development', :charset => :big5

[ show source ]

     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 410
410:       def create_database(name, options = {})
411:         if options[:collation]
412:           execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}` COLLATE `#{options[:collation]}`"
413:         else
414:           execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}`"
415:         end
416:       end
create_savepoint()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 359
359:       def create_savepoint
360:         execute("SAVEPOINT #{current_savepoint_name}")
361:       end
current_database()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 422
422:       def current_database
423:         select_value 'SELECT DATABASE() as db'
424:       end
disconnect!()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 296
296:       def disconnect!
297:         @connection.close rescue nil
298:       end
drop_table(table_name, options = {})

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 444
444:       def drop_table(table_name, options = {})
445:         super(table_name, options)
446:       end
limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 563
563:       def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)
564:         where_sql
565:       end
quote(value, column = nil)

QUOTING ==================================================

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 228
228:       def quote(value, column = nil)
229:         if value.kind_of?(String) && column && column.type == :binary && column.class.respond_to?(:string_to_binary)
230:           s = column.class.string_to_binary(value).unpack("H*")[0]
231:           "x'#{s}'"
232:         elsif value.kind_of?(BigDecimal)
233:           value.to_s("F")
234:         else
235:           super
236:         end
237:       end
quoted_false()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 255
255:       def quoted_false
256:         QUOTED_FALSE
257:       end
quoted_true()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 251
251:       def quoted_true
252:         QUOTED_TRUE
253:       end
reconnect!()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 291
291:       def reconnect!
292:         disconnect!
293:         connect
294:       end
release_savepoint()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 367
367:       def release_savepoint
368:         execute("RELEASE SAVEPOINT #{current_savepoint_name}")
369:       end
rename_table(table_name, new_name)

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 478
478:       def rename_table(table_name, new_name)
479:         execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
480:       end
reset!()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 300
300:       def reset!
301:         if @connection.respond_to?(:change_user)
302:           # See http://bugs.mysql.com/bug.php?id=33540 -- the workaround way to
303:           # reset the connection is to change the user to the same user.
304:           @connection.change_user(@config[:username], @config[:password], @config[:database])
305:           configure_connection
306:         end
307:       end
rollback_to_savepoint()

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 363
363:       def rollback_to_savepoint
364:         execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
365:       end
select_rows(sql, name = nil)

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

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 311
311:       def select_rows(sql, name = nil)
312:         @connection.query_with_result = true
313:         result = execute(sql, name)
314:         rows = []
315:         result.each { |row| rows << row }
316:         result.free
317:         rows
318:       end
show_variable(name)

SHOW VARIABLES LIKE ‘name‘

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 543
543:       def show_variable(name)
544:         variables = select_all("SHOW VARIABLES LIKE '#{name}'")
545:         variables.first['Value'] unless variables.empty?
546:       end
type_to_sql(type, limit = nil, precision = nil, scale = nil)

Maps logical Rails types to MySQL-specific data types.

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     # File vendor/rails/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 528
528:       def type_to_sql(type, limit = nil, precision = nil, scale = nil)
529:         return super unless type.to_s == 'integer'
530: 
531:         case limit
532:         when 1; 'tinyint'
533:         when 2; 'smallint'
534:         when 3; 'mediumint'
535:         when nil, 4, 11; 'int(11)'  # compatibility with MySQL default
536:         when 5..8; 'bigint'
537:         else raise(ActiveRecordError, "No integer type has byte size #{limit}")
538:         end
539:       end