Class: ActiveRecord::ConnectionAdapters::MysqlAdapter

Inherits:
AbstractAdapter show all
Defined in:
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.

Constant Summary collapse

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" ]
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 }
}

Instance Attribute Summary

Attributes included from QueryCache

#query_cache, #query_cache_enabled

Instance Method Summary collapse

Methods inherited from AbstractAdapter

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

Methods included from QueryCache

#cache, #clear_query_cache, #columns_with_query_cache, dirties_query_cache, included, #select_all_with_query_cache, #uncached

Methods included from Quoting

#quoted_date, #quoted_string_prefix

Methods included from DatabaseStatements

#add_limit!, #add_lock!, #default_sequence_name, #delete, #empty_insert_statement, #insert, #insert_fixture, #outside_transaction?, #reset_sequence!, #select_all, #select_one, #select_value, #select_values, #transaction, #update

Methods included from SchemaStatements

#add_column, #add_column_options!, #add_index, #add_order_by_for_association_limiting!, #add_timestamps, #assume_migrated_upto_version, #change_table, #distinct, #dump_schema_information, #index_name, #initialize_schema_migrations_table, #remove_column, #remove_index, #remove_timestamps, #table_alias_for, #table_alias_length, #table_exists?

Constructor Details

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

Returns a new instance of MysqlAdapter.



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 200

def initialize(connection, logger, connection_options, config)
  super(connection, logger)
  @connection_options, @config = connection_options, config
  @quoted_column_names, @quoted_table_names = {}, {}
  connect
end

Instance Method Details

#active? ⇒ Boolean

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

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 272

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:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 207

def adapter_name #:nodoc:
  ADAPTER_NAME
end

#add_limit_offset!(sql, options) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 369

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

#begin_db_transaction ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 339

def begin_db_transaction #:nodoc:
  execute "BEGIN"
rescue Exception
  # Transactions aren't supported
end

#case_sensitive_equality_operator ⇒ Object 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 557

def case_sensitive_equality_operator
  "= BINARY"
end

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

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 495

def change_column(table_name, column_name, type, options = {}) #:nodoc:
  column = column_for(table_name, column_name)

  unless options_include_default?(options)
    options[:default] = column.default
  end

  unless options.has_key?(:null)
    options[:null] = column.null
  end

  change_column_sql = "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
  add_column_options!(change_column_sql, options)
  execute(change_column_sql)
end

#change_column_default(table_name, column_name, default) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 480

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 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 485

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.



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 425

def charset
  show_variable 'character_set_database'
end

#collation ⇒ Object

Returns the database collation strategy.



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 430

def collation
  show_variable 'collation_database'
end

#columns(table_name, name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 463

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

#commit_db_transaction ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 345

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 408

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 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 357

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

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

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 472

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

#current_database ⇒ Object 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 420

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

#disable_referential_integrity(&block) ⇒ Object

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 259

def disable_referential_integrity(&block) #: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 



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

def disconnect!
  @connection.close rescue nil
end

#drop_database(name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 416

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

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



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

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 environment.rb file:

ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans = false



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 172

cattr_accessor :emulate_booleans

#execute(sql, name = nil) ⇒ Object

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 319

def execute(sql, name = nil) #:nodoc:
  log(sql, name) { @connection.query(sql) }
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

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 446

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]
  end
  result.free
  indexes
end

#insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 329

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

#limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key) ⇒ Object 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 561

def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)
  where_sql
end

#native_database_types ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 219

def native_database_types #:nodoc:
  NATIVE_DATABASE_TYPES
end

#pk_and_sequence_for(table) ⇒ Object

Returns a table’s primary key and belonging sequence.



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 547

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

#quote(value, column = nil) ⇒ Object

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 226

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:



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

def quote_column_name(name) #:nodoc:
  @quoted_column_names[name] ||= "`#{name}`"
end

#quote_string(string) ⇒ Object

:nodoc:



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

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

#quote_table_name(name) ⇒ Object

:nodoc:



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

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

#quoted_false ⇒ Object 



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

def quoted_false
  QUOTED_FALSE
end

#quoted_true ⇒ Object 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 249

def quoted_true
  QUOTED_TRUE
end

#reconnect! ⇒ Object 



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

def reconnect!
  disconnect!
  connect
end

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

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 396

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

#release_savepoint ⇒ Object 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 365

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

#rename_column(table_name, column_name, new_column_name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 511

def rename_column(table_name, column_name, new_column_name) #:nodoc:
  options = {}
  if column = columns(table_name).find { |c| c.name == column_name.to_s }
    options[:default] = column.default
    options[:null] = column.null
  else
    raise ActiveRecordError, "No such column: #{table_name}.#{column_name}"
  end
  current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"]
  rename_column_sql = "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}"
  add_column_options!(rename_column_sql, options)
  execute(rename_column_sql)
end

#rename_table(table_name, new_name) ⇒ Object 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 476

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

#reset! ⇒ Object 



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

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:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 351

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

#rollback_to_savepoint ⇒ Object 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 361

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

#select_rows(sql, name = nil) ⇒ Object

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 309

def select_rows(sql, name = nil)
  @connection.query_with_result = true
  result = execute(sql, name)
  rows = []
  result.each { |row| rows << row }
  result.free
  rows
end

#show_variable(name) ⇒ Object

SHOW VARIABLES LIKE ‘name’



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 541

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

#structure_dump ⇒ Object

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 383

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

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

#supports_migrations? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 211

def supports_migrations? #:nodoc:
  true
end

#supports_savepoints? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 215

def supports_savepoints? #:nodoc:
  true
end

#tables(name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 434

def tables(name = nil) #:nodoc:
  tables = []
  result = execute("SHOW TABLES", name)
  result.each { |field| tables << field[0] }
  result.free
  tables
end

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

Maps logical Rails types to MySQL-specific data types.



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 526

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:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 334

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