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

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 <tommy@tmtm.org>

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

Instance Attribute Summary

Attributes inherited from AbstractAdapter

#visitor

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 inherited from QueryCache

#call

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 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

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 Quoting

#quoted_date

Constructor Details

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



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# 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:



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# 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 ====================================



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# 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_nameObject

:nodoc:



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# 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



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# 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



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# 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:



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# 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_transactionObject

:nodoc:



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# 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:



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# 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_operatorObject



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

def case_sensitive_equality_operator
  "= BINARY"
end

#case_sensitive_modifier(node) ⇒ Object



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# 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:



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# 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:



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# 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



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# 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

#charsetObject

Returns the database character set.



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# 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.



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

def clear_cache!
  @statements.clear
end

#client_encodingObject

Get the client encoding for this database



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# 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

#collationObject

Returns the database collation strategy.



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# 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.



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# 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_transactionObject

:nodoc:



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# 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


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# 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_savepointObject



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# 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:



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# 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_databaseObject



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

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

#disable_referential_integrityObject

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



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# 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.



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# 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'


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# 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



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

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

#emulate_booleansObject

: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


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# 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



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# 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



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# 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:



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# 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.



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# 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.



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# 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:



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# 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!



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# 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



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# 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



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# 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_typesObject

:nodoc:



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# 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.



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# 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



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# 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 ==================================================



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# 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:



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# 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:



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# 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:



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# 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_falseObject



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

def quoted_false
  QUOTED_FALSE
end

#quoted_trueObject



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

def quoted_true
  QUOTED_TRUE
end

#reconnect!Object



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# 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.



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# 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_savepointObject



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# 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:



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# 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')


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# 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



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# 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_transactionObject

:nodoc:



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# 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_savepointObject



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# 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 ======================================



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# 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'



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# 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_dumpObject

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



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# 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:



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# 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.



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

def supports_migrations? #:nodoc:
  true
end

#supports_primary_key?Boolean

Returns true.



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# 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.



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# 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.



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

def supports_statement_cache?
  true
end

#table_exists?(name) ⇒ Boolean



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# 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:



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# 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



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# 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.



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# 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:



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

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