Class: ActiveRecord::ConnectionAdapters::MysqlAdapter

Inherits:
AbstractAdapter show all
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).

  • :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.

Defined Under Namespace

Classes: StatementPool

Constant Summary collapse

ADAPTER_NAME = 
'MySQL'
LOST_CONNECTION_ERROR_MESSAGES = 
[
"Server shutdown in progress",
"Broken pipe",
"Lost connection to MySQL server during query",
"MySQL server has gone away" ]
NATIVE_DATABASE_TYPES = 
{
  :primary_key => "int(11) DEFAULT NULL auto_increment PRIMARY KEY",
  :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 }
}
ENCODINGS =

Taken from here:

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

Author: TOMITA Masahiro <[email protected]>

Hash.new { |h,k| h[k] = k }

Instance Attribute Summary

Attributes inherited from AbstractAdapter

#visitor

Attributes included from QueryCache

#query_cache, #query_cache_enabled

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from AbstractAdapter

#current_savepoint_name, #decrement_open_transactions, #increment_open_transactions, #open_transactions, #prefetch_primary_key?, #raw_connection, #requires_reloading?, #substitute_at, #supports_count_distinct?, #supports_ddl_transactions?, #transaction_joinable=, #verify!

Methods included from ActiveSupport::Callbacks

#run_callbacks

Methods included from ActiveSupport::Concern

#append_features, extended, #included

Methods included from QueryCache

#cache, #clear_query_cache, dirties_query_cache, #disable_query_cache!, #enable_query_cache!, included, #select_all, #uncached

Methods included from DatabaseLimits

#column_name_length, #columns_per_multicolumn_index, #columns_per_table, #in_clause_length, #index_name_length, #indexes_per_table, #joins_per_query, #sql_query_length, #table_alias_length, #table_name_length

Methods included from Quoting

#quoted_date

Methods included from DatabaseStatements

#add_transaction_record, #default_sequence_name, #delete, #empty_insert_statement_value, #exec_insert, #insert, #insert_fixture, #outside_transaction?, #reset_sequence!, #sanitize_limit, #select_all, #select_one, #select_value, #select_values, #to_sql, #transaction, #update

Methods included from SchemaStatements

#add_column_options!, #add_index, #add_timestamps, #assume_migrated_upto_version, #change_table, #column_exists?, #distinct, #dump_schema_information, #index_exists?, #index_name, #index_name_exists?, #initialize_schema_migrations_table, #remove_column, #remove_index, #remove_index!, #remove_timestamps, #rename_index, #table_alias_for

Constructor Details

#initialize(connection, logger, connection_options, config) ⇒ MysqlAdapter

Returns a new instance of MysqlAdapter.



220
221
222
223
224
225
226
227
228
229
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 220

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

Class Method Details

.visitor_for(pool) ⇒ Object

:nodoc:



231
232
233
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 231

def self.visitor_for(pool) # :nodoc:
  Arel::Visitors::MySQL.new(pool)
end

Instance Method Details

#active? ⇒ Boolean

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

Returns:

  • (Boolean) 


323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 323

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

#adapter_name ⇒ Object

:nodoc:



235
236
237
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 235

def adapter_name #:nodoc:
  ADAPTER_NAME
end

#add_column(table_name, column_name, type, options = {}) ⇒ Object 



701
702
703
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 701

def add_column(table_name, column_name, type, options = {})
  execute("ALTER TABLE #{quote_table_name(table_name)} #{add_column_sql(table_name, column_name, type, options)}")
end

#add_column_position!(sql, options) ⇒ Object 



742
743
744
745
746
747
748
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 742

def add_column_position!(sql, options)
  if options[:first]
    sql << " FIRST"
  elsif options[:after]
    sql << " AFTER #{quote_column_name(options[:after])}"
  end
end

#add_limit_offset!(sql, options) ⇒ Object

:nodoc:



527
528
529
530
531
532
533
534
535
536
537
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 527

def add_limit_offset!(sql, options) #:nodoc:
  limit, offset = options[:limit], options[:offset]
  if limit && offset
    sql << " LIMIT #{offset.to_i}, #{sanitize_limit(limit)}"
  elsif limit
    sql << " LIMIT #{sanitize_limit(limit)}"
  elsif offset
    sql << " OFFSET #{offset.to_i}"
  end
  sql
end

#begin_db_transaction ⇒ Object

:nodoc:



497
498
499
500
501
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 497

def begin_db_transaction #:nodoc:
  exec_without_stmt "BEGIN"
rescue Mysql::Error
  # Transactions aren't supported
end

#bulk_change_table(table_name, operations) ⇒ Object

:nodoc:



686
687
688
689
690
691
692
693
694
695
696
697
698
699
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 686

def bulk_change_table(table_name, operations) #:nodoc:
  sqls = operations.map do |command, args|
    table, arguments = args.shift, args
    method = :"#{command}_sql"

    if respond_to?(method)
      send(method, table, *arguments)
    else
      raise "Unknown method called : #{method}(#{arguments.inspect})"
    end
  end.flatten.join(", ")

  execute("ALTER TABLE #{quote_table_name(table_name)} #{sqls}")
end

#case_sensitive_equality_operator ⇒ Object 



773
774
775
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 773

def case_sensitive_equality_operator
  "= BINARY"
end

#case_sensitive_modifier(node) ⇒ Object 



778
779
780
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 778

def case_sensitive_modifier(node)
  Arel::Nodes::Bin.new(node)
end

#change_column(table_name, column_name, type, options = {}) ⇒ Object

:nodoc:



720
721
722
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 720

def change_column(table_name, column_name, type, options = {}) #:nodoc:
  execute("ALTER TABLE #{quote_table_name(table_name)} #{change_column_sql(table_name, column_name, type, options)}")
end

#change_column_default(table_name, column_name, default) ⇒ Object

:nodoc:



705
706
707
708
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 705

def change_column_default(table_name, column_name, default) #:nodoc:
  column = column_for(table_name, column_name)
  change_column table_name, column_name, column.sql_type, :default => default
end

#change_column_null(table_name, column_name, null, default = nil) ⇒ Object 



710
711
712
713
714
715
716
717
718
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 710

def change_column_null(table_name, column_name, null, default = nil)
  column = column_for(table_name, column_name)

  unless null || default.nil?
    execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
  end

  change_column table_name, column_name, column.sql_type, :null => null
end

#charset ⇒ Object

Returns the database character set.



612
613
614
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 612

def charset
  show_variable 'character_set_database'
end

#clear_cache! ⇒ Object

Clears the prepared statements cache.



371
372
373
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 371

def clear_cache!
  @statements.clear
end

#client_encoding ⇒ Object

Get the client encoding for this database



423
424
425
426
427
428
429
430
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 423

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

#collation ⇒ Object

Returns the database collation strategy.



617
618
619
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 617

def collation
  show_variable 'collation_database'
end

#columns(table_name, name = nil) ⇒ Object

Returns an array of MysqlColumn objects for the table specified by table_name.



666
667
668
669
670
671
672
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 666

def columns(table_name, name = nil)#:nodoc:
  sql = "SHOW FIELDS FROM #{quote_table_name(table_name)}"
  result = execute(sql, 'SCHEMA')
  columns = result.collect { |field| MysqlColumn.new(field[0], field[4], field[1], field[2] == "YES") }
  result.free
  columns
end

#commit_db_transaction ⇒ Object

:nodoc:



503
504
505
506
507
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 503

def commit_db_transaction #:nodoc:
  execute "COMMIT"
rescue Exception
  # Transactions aren't supported
end

#create_database(name, options = {}) ⇒ Object

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



591
592
593
594
595
596
597
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 591

def create_database(name, options = {})
  if options[:collation]
    execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}` COLLATE `#{options[:collation]}`"
  else
    execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}`"
  end
end

#create_savepoint ⇒ Object 



515
516
517
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 515

def create_savepoint
  execute("SAVEPOINT #{current_savepoint_name}")
end

#create_table(table_name, options = {}) ⇒ Object

:nodoc:



674
675
676
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 674

def create_table(table_name, options = {}) #:nodoc:
  super(table_name, options.reverse_merge(:options => "ENGINE=InnoDB"))
end

#current_database ⇒ Object 



607
608
609
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 607

def current_database
  select_value 'SELECT DATABASE() as db'
end

#disable_referential_integrity ⇒ Object

REFERENTIAL INTEGRITY ====================================



310
311
312
313
314
315
316
317
318
319
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 310

def disable_referential_integrity #:nodoc:
  old = select_value("SELECT @@FOREIGN_KEY_CHECKS")

  begin
    update("SET FOREIGN_KEY_CHECKS = 0")
    yield
  ensure
    update("SET FOREIGN_KEY_CHECKS = #{old}")
  end
end

#disconnect! ⇒ Object

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



348
349
350
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 348

def disconnect!
  @connection.close rescue nil
end

#drop_database(name) ⇒ Object

Drops a MySQL database.

Example:

drop_database 'sebastian_development'



603
604
605
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 603

def drop_database(name) #:nodoc:
  execute "DROP DATABASE IF EXISTS `#{name}`"
end

#drop_table(table_name, options = {}) ⇒ Object 



642
643
644
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 642

def drop_table(table_name, options = {})
  super(table_name, options)
end

#emulate_booleans ⇒ Object

:singleton-method: By default, the MysqlAdapter will consider all columns of type tinyint(1) as boolean. If you wish to disable this emulation (which was the default behavior in versions 0.13.1 and earlier) you can add the following line to your application.rb file:

ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans = false



160
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 160

cattr_accessor :emulate_booleans

#exec_delete(sql, name, binds) ⇒ Object Also known as: exec_update 



488
489
490
491
492
493
494
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 488

def exec_delete(sql, name, binds)
  log(sql, name, binds) do
    exec_stmt(sql, name, binds) do |cols, stmt|
      stmt.affected_rows
    end
  end
end

#exec_query(sql, name = 'SQL', binds = []) ⇒ Object 



432
433
434
435
436
437
438
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 432

def exec_query(sql, name = 'SQL', binds = [])
  log(sql, name, binds) do
    exec_stmt(sql, name, binds) do |cols, stmt|
      ActiveRecord::Result.new(cols, stmt.to_a) if cols
    end
  end
end

#exec_without_stmt(sql, name = 'SQL') ⇒ Object

:nodoc:



444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 444

def exec_without_stmt(sql, name = 'SQL') # :nodoc:
  # Some queries, like SHOW CREATE TABLE don't work through the prepared
  # statement API.  For those queries, we need to use this method. :'(
  log(sql, name) do
    result = @connection.query(sql)
    cols = []
    rows = []

    if result
      cols = result.fetch_fields.map { |field| field.name }
      rows = result.to_a
      result.free
    end
    ActiveRecord::Result.new(cols, rows)
  end
end

#execute(sql, name = nil) ⇒ Object

Executes an SQL query and returns a MySQL::Result object. Note that you have to free the Result object after you’re done using it.



463
464
465
466
467
468
469
470
471
472
473
474
475
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 463

def execute(sql, name = nil) #:nodoc:
  if name == :skip_logging
    @connection.query(sql)
  else
    log(sql, name) { @connection.query(sql) }
  end
rescue ActiveRecord::StatementInvalid => exception
  if exception.message.split(":").first =~ /Packets out of order/
    raise ActiveRecord::StatementInvalid, "'Packets out of order' error was received from the database. Please update your mysql bindings (gem install mysql) and read http://dev.mysql.com/doc/mysql/en/password-hashing.html for more information.  If you're on Windows, use the Instant Rails installer to get the updated mysql bindings."
  else
    raise
  end
end

#indexes(table_name, name = nil) ⇒ Object

Returns an array of indexes for the given table.



647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 647

def indexes(table_name, name = nil)#:nodoc:
  indexes = []
  current_index = nil
  result = execute("SHOW KEYS FROM #{quote_table_name(table_name)}", name)
  result.each do |row|
    if current_index != row[2]
      next if row[2] == "PRIMARY" # skip the primary key
      current_index = row[2]
      indexes << IndexDefinition.new(row[0], row[2], row[1] == "0", [], [])
    end

    indexes.last.columns << row[4]
    indexes.last.lengths << row[7]
  end
  result.free
  indexes
end

#insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object Also known as: create

:nodoc:



477
478
479
480
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 477

def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) #:nodoc:
  super sql, name
  id_value || @connection.insert_id
end

#join_to_update(update, select) ⇒ Object

In the simple case, MySQL allows us to place JOINs directly into the UPDATE query. However, this does not allow for LIMIT, OFFSET and ORDER. To support these, we must use a subquery. However, MySQL is too stupid to create a temporary table for this automatically, so we have to give it some prompting in the form of a subsubquery. Ugh!



545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 545

def join_to_update(update, select) #:nodoc:
  if select.limit || select.offset || select.orders.any?
    subsubselect = select.clone
    subsubselect.projections = [update.key]

    subselect = Arel::SelectManager.new(select.engine)
    subselect.project Arel.sql(update.key.name)
    subselect.from subsubselect.as('__active_record_temp')

    update.where update.key.in(subselect)
  else
    update.table select.source
    update.wheres = select.constraints
  end
end

#last_inserted_id(result) ⇒ Object 



440
441
442
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 440

def last_inserted_id(result)
  @connection.insert_id
end

#limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key) ⇒ Object 



782
783
784
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 782

def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)
  where_sql
end

#native_database_types ⇒ Object

:nodoc:



264
265
266
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 264

def native_database_types #:nodoc:
  NATIVE_DATABASE_TYPES
end

#pk_and_sequence_for(table) ⇒ Object

Returns a table’s primary key and belonging sequence.



757
758
759
760
761
762
763
764
765
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 757

def pk_and_sequence_for(table) #:nodoc:
  keys = []
  result = execute("describe #{quote_table_name(table)}", 'SCHEMA')
  result.each_hash do |h|
    keys << h["Field"]if h["Key"] == "PRI"
  end
  result.free
  keys.length == 1 ? [keys.first, nil] : nil
end

#primary_key(table) ⇒ Object

Returns just a table’s primary key



768
769
770
771
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 768

def primary_key(table)
  pk_and_sequence = pk_and_sequence_for(table)
  pk_and_sequence && pk_and_sequence.first
end

#quote(value, column = nil) ⇒ Object

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



271
272
273
274
275
276
277
278
279
280
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 271

def quote(value, column = nil)
  if value.kind_of?(String) && column && column.type == :binary && column.class.respond_to?(:string_to_binary)
    s = column.class.string_to_binary(value).unpack("H*")[0]
    "x'#{s}'"
  elsif value.kind_of?(BigDecimal)
    value.to_s("F")
  else
    super
  end
end

#quote_column_name(name) ⇒ Object

:nodoc:



288
289
290
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 288

def quote_column_name(name) #:nodoc:
  @quoted_column_names[name] ||= "`#{name.to_s.gsub('`', '``')}`"
end

#quote_string(string) ⇒ Object

:nodoc:



296
297
298
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 296

def quote_string(string) #:nodoc:
  @connection.quote(string)
end

#quote_table_name(name) ⇒ Object

:nodoc:



292
293
294
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 292

def quote_table_name(name) #:nodoc:
  @quoted_table_names[name] ||= quote_column_name(name).gsub('.', '`.`')
end

#quoted_false ⇒ Object 



304
305
306
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 304

def quoted_false
  QUOTED_FALSE
end

#quoted_true ⇒ Object 



300
301
302
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 300

def quoted_true
  QUOTED_TRUE
end

#reconnect! ⇒ Object 



340
341
342
343
344
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 340

def reconnect!
  disconnect!
  clear_cache!
  connect
end

#recreate_database(name, options = {}) ⇒ Object

Drops the database specified on the name attribute and creates it again using the provided options.



579
580
581
582
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 579

def recreate_database(name, options = {}) #:nodoc:
  drop_database(name)
  create_database(name, options)
end

#release_savepoint ⇒ Object 



523
524
525
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 523

def release_savepoint
  execute("RELEASE SAVEPOINT #{current_savepoint_name}")
end

#rename_column(table_name, column_name, new_column_name) ⇒ Object

:nodoc:



724
725
726
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 724

def rename_column(table_name, column_name, new_column_name) #:nodoc:
  execute("ALTER TABLE #{quote_table_name(table_name)} #{rename_column_sql(table_name, column_name, new_column_name)}")
end

#rename_table(table_name, new_name) ⇒ Object

Renames a table.

Example:

rename_table('octopuses', 'octopi')



682
683
684
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 682

def rename_table(table_name, new_name)
  execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
end

#reset! ⇒ Object 



352
353
354
355
356
357
358
359
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 352

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

#rollback_db_transaction ⇒ Object

:nodoc:



509
510
511
512
513
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 509

def rollback_db_transaction #:nodoc:
  execute "ROLLBACK"
rescue Exception
  # Transactions aren't supported
end

#rollback_to_savepoint ⇒ Object 



519
520
521
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 519

def rollback_to_savepoint
  execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
end

#select_rows(sql, name = nil) ⇒ Object

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



363
364
365
366
367
368
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 363

def select_rows(sql, name = nil)
  @connection.query_with_result = true
  rows = exec_without_stmt(sql, name).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

#show_variable(name) ⇒ Object

SHOW VARIABLES LIKE ‘name’



751
752
753
754
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 751

def show_variable(name)
  variables = select_all("SHOW VARIABLES LIKE '#{name}'")
  variables.first['Value'] unless variables.empty?
end

#structure_dump ⇒ Object

SCHEMA STATEMENTS ========================================



563
564
565
566
567
568
569
570
571
572
573
574
575
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 563

def structure_dump #:nodoc:
  if supports_views?
    sql = "SHOW FULL TABLES WHERE Table_type = 'BASE TABLE'"
  else
    sql = "SHOW TABLES"
  end

  select_all(sql).map do |table|
    table.delete('Table_type')
    sql = "SHOW CREATE TABLE #{quote_table_name(table.to_a.first.last)}"
    exec_without_stmt(sql).first['Create Table'] + ";\n\n"
  end.join("")
end

#supports_bulk_alter? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


239
240
241
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 239

def supports_bulk_alter? #:nodoc:
  true
end

#supports_migrations? ⇒ Boolean

Returns true, since this connection adapter supports migrations.

Returns:

  • (Boolean) 


250
251
252
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 250

def supports_migrations? #:nodoc:
  true
end

#supports_primary_key? ⇒ Boolean

Returns true.

Returns:

  • (Boolean) 


255
256
257
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 255

def supports_primary_key? #:nodoc:
  true
end

#supports_savepoints? ⇒ Boolean

Returns true, since this connection adapter supports savepoints.

Returns:

  • (Boolean) 


260
261
262
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 260

def supports_savepoints? #:nodoc:
  true
end

#supports_statement_cache? ⇒ Boolean

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

Returns:

  • (Boolean) 


245
246
247
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 245

def supports_statement_cache?
  true
end

#table_exists?(name) ⇒ Boolean

Returns:

  • (Boolean) 


628
629
630
631
632
633
634
635
636
637
638
639
640
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 628

def table_exists?(name)
  return true if super

  name          = name.to_s
  schema, table = name.split('.', 2)

  unless table # A table was provided without a schema
    table  = schema
    schema = nil
  end

  tables(nil, schema).include? table
end

#tables(name = nil, database = nil) ⇒ Object

:nodoc:



621
622
623
624
625
626
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 621

def tables(name = nil, database = nil) #:nodoc:
  result = execute(["SHOW TABLES", database].compact.join(' IN '), 'SCHEMA')
  tables = result.collect { |field| field[0] }
  result.free
  tables
end

#type_cast(value, column) ⇒ Object 



282
283
284
285
286
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 282

def type_cast(value, column)
  return super unless value == true || value == false

  value ? 1 : 0
end

#type_to_sql(type, limit = nil, precision = nil, scale = nil) ⇒ Object

Maps logical Rails types to MySQL-specific data types.



729
730
731
732
733
734
735
736
737
738
739
740
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 729

def type_to_sql(type, limit = nil, precision = nil, scale = nil)
  return super unless type.to_s == 'integer'

  case limit
  when 1; 'tinyint'
  when 2; 'smallint'
  when 3; 'mediumint'
  when nil, 4, 11; 'int(11)'  # compatibility with MySQL default
  when 5..8; 'bigint'
  else raise(ActiveRecordError, "No integer type has byte size #{limit}")
  end
end

#update_sql(sql, name = nil) ⇒ Object

:nodoc:



483
484
485
486
 
# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 483

def update_sql(sql, name = nil) #:nodoc:
  super
  @connection.affected_rows
end