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

  • :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

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

Constant Summary collapse

LOST_CONNECTION_ERROR_MESSAGES = 
[
  "Server shutdown in progress",
  "Broken pipe",
  "Lost connection to MySQL server during query",
  "MySQL server has gone away"
]
@@emulate_booleans = 
true

Instance Method Summary collapse

Methods inherited from AbstractAdapter

#log_info, #prefetch_primary_key?, #raw_connection, #requires_reloading?, #reset_runtime, #supports_count_distinct?, #verify!

Methods included from QueryCache

#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, #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!, #distinct, #dump_schema_information, #index_name, #initialize_schema_information, #remove_column, #remove_index, #table_alias_for, #table_alias_length, #type_to_sql

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 161

def initialize(connection, logger, connection_options, config)
  super(connection, logger)
  @connection_options, @config = connection_options, config

  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 242

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 168

def adapter_name #:nodoc:
  'MySQL'
end

#add_limit_offset!(sql, options) ⇒ Object

:nodoc:



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

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

#begin_db_transaction ⇒ Object

:nodoc:



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

def begin_db_transaction #:nodoc:
  execute "BEGIN"
rescue Exception
  # Transactions aren't supported
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 429

def change_column(table_name, column_name, type, options = {}) #:nodoc:
  unless options_include_default?(options)
    if column = columns(table_name).find { |c| c.name == column_name.to_s }
      options[:default] = column.default
    else
      raise "No such column: #{table_name}.#{column_name}"
    end
  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 423

def change_column_default(table_name, column_name, default) #:nodoc:
  current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"]

  execute("ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(column_name)} #{current_type} DEFAULT #{quote(default)}")
end

#charset ⇒ Object

Returns the database character set.



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 374

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 379

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 408

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

#commit_db_transaction ⇒ Object

:nodoc:



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

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 357

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_table(table_name, options = {}) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 415

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 369

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 229

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 264

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 365

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 389

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

#execute(sql, name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 280

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 393

def indexes(table_name, name = nil)#:nodoc:
  indexes = []
  current_index = nil
  execute("SHOW KEYS FROM #{quote_table_name(table_name)}", name).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
  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 290

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

#native_database_types ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 176

def native_database_types #:nodoc:
  {
    :primary_key => "int(11) DEFAULT NULL auto_increment PRIMARY KEY",
    :string      => { :name => "varchar", :limit => 255 },
    :text        => { :name => "text" },
    :integer     => { :name => "int", :limit => 11 },
    :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 }
  }
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 456

def pk_and_sequence_for(table) #:nodoc:
  keys = []
  execute("describe #{quote_table_name(table)}").each_hash do |h|
    keys << h["Field"]if h["Key"] == "PRI"
  end
  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 196

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 207

def quote_column_name(name) #:nodoc:
  "`#{name}`"
end

#quote_string(string) ⇒ Object

:nodoc:



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

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 211

def quote_table_name(name) #:nodoc:
  quote_column_name(name).gsub('.', '`.`')
end

#quoted_false ⇒ Object 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 223

def quoted_false
  "0"
end

#quoted_true ⇒ Object 



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

def quoted_true
  "1"
end

#reconnect! ⇒ Object 



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

def reconnect!
  disconnect!
  connect
end

#recreate_database(name) ⇒ Object

:nodoc:



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

def recreate_database(name) #:nodoc:
  drop_database(name)
  create_database(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 443

def rename_column(table_name, column_name, new_column_name) #:nodoc:
  current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"]
  execute "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}"
end

#rename_table(table_name, new_name) ⇒ Object 



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 419

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

#rollback_db_transaction ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 312

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

#select_rows(sql, name = nil) ⇒ Object

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 271

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 450

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 332

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 172

def supports_migrations? #:nodoc:
  true
end

#tables(name = nil) ⇒ Object

:nodoc:



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

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

#update_sql(sql, name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 295

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