Methods
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P
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T
Constants
LOST_CONNECTION_ERROR_MESSAGES = [ "Server shutdown in progress", "Broken pipe", "Lost connection to MySQL server during query", "MySQL server has gone away" ]
 
QUOTED_FALSE = '1', '0'
 
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 } }
 
Class Public methods
emulate_booleans

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::Mysql[2]Adapter.emulate_booleans = false
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 100
class_attribute :emulate_booleans
new(connection, logger, connection_options, config)

FIXME: Make the first parameter more similar for the two adapters

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 131
def initialize(connection, logger, connection_options, config)
  super(connection, logger)
  @connection_options, @config = connection_options, config
  @quoted_column_names, @quoted_table_names = {}, {}

  if config.fetch(:prepared_statements) { true }
    @visitor = Arel::Visitors::MySQL.new self
  else
    @visitor = BindSubstitution.new self
  end
end
Instance Public methods
add_column(table_name, column_name, type, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 458
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)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 510
def add_column_position!(sql, options)
  if options[:first]
    sql << " FIRST"
  elsif options[:after]
    sql << " AFTER #{quote_column_name(options[:after])}"
  end
end
begin_db_transaction()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 265
def begin_db_transaction
  execute "BEGIN"
rescue Exception
  # Transactions aren't supported
end
case_insensitive_comparison(table, attribute, column, value)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 547
def case_insensitive_comparison(table, attribute, column, value)
  if column.case_sensitive?
    super
  else
    table[attribute].eq(value)
  end
end
case_sensitive_modifier(node)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 543
def case_sensitive_modifier(node)
  Arel::Nodes::Bin.new(node)
end
change_column_default(table_name, column_name, default)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 462
def change_column_default(table_name, column_name, default)
  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)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 467
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()

Returns the database character set.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 367
def charset
  show_variable 'character_set_database'
end
collation()

Returns the database collation strategy.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 372
def collation
  show_variable 'collation_database'
end
create_database(name, options = {})

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

Example:

create_database 'charset_test', :charset => 'latin1', :collation => 'latin1_bin'
create_database 'matt_development'
create_database 'matt_development', :charset => :big5
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 346
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()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 283
def create_savepoint
  execute("SAVEPOINT #{current_savepoint_name}")
end
current_database()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 362
def current_database
  select_value 'SELECT DATABASE() as db'
end
execute(sql, name = nil)

Executes the SQL statement in the context of this connection.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 239
def execute(sql, name = nil)
  if name == :skip_logging
    @connection.query(sql)
  else
    log(sql, name) { @connection.query(sql) }
  end
rescue ActiveRecord::StatementInvalid => exception
  if exception.message.split(":").first =~ %rPackets 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
limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 555
def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)
  where_sql
end
native_database_types()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 171
def native_database_types
  NATIVE_DATABASE_TYPES
end
pk_and_sequence_for(table)

Returns a table’s primary key and belonging sequence.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 525
def pk_and_sequence_for(table)
  execute_and_free("SHOW CREATE TABLE #{quote_table_name(table)}", 'SCHEMA') do |result|
    create_table = each_hash(result).first[:"Create Table"]
    if create_table.to_s =~ %rPRIMARY KEY\s+(?:USING\s+\w+\s+)?\((.+)\)/
      keys = $1.split(",").map { |key| key.gsub(%r[`"]/, "") }
      keys.length == 1 ? [keys.first, nil] : nil
    else
      nil
    end
  end
end
primary_key(table)

Returns just a table’s primary key

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 538
def primary_key(table)
  pk_and_sequence = pk_and_sequence_for(table)
  pk_and_sequence && pk_and_sequence.first
end
quote(value, column = nil)

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

# File activerecord/lib/active_record/connection_adapters/abstract_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
quoted_false()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 219
def quoted_false
  QUOTED_FALSE
end
quoted_true()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 215
def quoted_true
  QUOTED_TRUE
end
recreate_database(name, options = {})

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

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 334
def recreate_database(name, options = {})
  drop_database(name)
  create_database(name, options)
end
release_savepoint()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 291
def release_savepoint
  execute("RELEASE SAVEPOINT #{current_savepoint_name}")
end
rename_table(table_name, new_name)

Renames a table.

Example:

rename_table('octopuses', 'octopi')
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 454
def rename_table(table_name, new_name)
  execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
end
rollback_to_savepoint()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 287
def rollback_to_savepoint
  execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
end
show_variable(name)

SHOW VARIABLES LIKE ‘name’

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 519
def show_variable(name)
  variables = select_all("SHOW VARIABLES LIKE '#{name}'")
  variables.first['Value'] unless variables.empty?
end
supports_index_sort_order?()

Technically MySQL allows to create indexes with the sort order syntax but at the moment (5.5) it doesn’t yet implement them

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 167
def supports_index_sort_order?
  true
end
supports_migrations?()

Returns true, since this connection adapter supports migrations.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 148
def supports_migrations?
  true
end
supports_primary_key?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 152
def supports_primary_key?
  true
end
supports_savepoints?()

Returns true, since this connection adapter supports savepoints.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 157
def supports_savepoints?
  true
end
table_exists?(name)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 386
def table_exists?(name)
  return false unless name
  return true if tables(nil, nil, name).any?

  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, table).any?
end
type_to_sql(type, limit = nil, precision = nil, scale = nil)

Maps logical Rails types to MySQL-specific data types.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 486
def type_to_sql(type, limit = nil, precision = nil, scale = nil)
  case type.to_s
  when '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
  when 'text'
    case limit
    when 0..0xff;               'tinytext'
    when nil, 0x100..0xffff;    'text'
    when 0x10000..0xffffff;     'mediumtext'
    when 0x1000000..0xffffffff; 'longtext'
    else raise(ActiveRecordError, "No text type has character length #{limit}")
    end
  else
    super
  end
end
Instance Protected methods
add_column_sql(table_name, column_name, type, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 597
def add_column_sql(table_name, column_name, type, options = {})
  add_column_sql = "ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
  add_column_options!(add_column_sql, options)
  add_column_position!(add_column_sql, options)
  add_column_sql
end
add_index_length(option_strings, column_names, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 561
def add_index_length(option_strings, column_names, options = {})
  if options.is_a?(Hash) && length = options[:length]
    case length
    when Hash
      column_names.each {|name| option_strings[name] += "(#{length[name]})" if length.has_key?(name) && length[name].present?}
    when Fixnum
      column_names.each {|name| option_strings[name] += "(#{length})"}
    end
  end

  return option_strings
end
add_index_sql(table_name, column_name, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 642
def add_index_sql(table_name, column_name, options = {})
  index_name, index_type, index_columns = add_index_options(table_name, column_name, options)
  "ADD #{index_type} INDEX #{index_name} (#{index_columns})"
end
add_timestamps_sql(table_name)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 652
def add_timestamps_sql(table_name)
  [add_column_sql(table_name, :created_at, :datetime), add_column_sql(table_name, :updated_at, :datetime)]
end
change_column_sql(table_name, column_name, type, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 604
def change_column_sql(table_name, column_name, type, options = {})
  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 = "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)
  add_column_position!(change_column_sql, options)
  change_column_sql
end
quoted_columns_for_index(column_names, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 574
def quoted_columns_for_index(column_names, options = {})
  option_strings = Hash[column_names.map {|name| [name, '']}]

  # add index length
  option_strings = add_index_length(option_strings, column_names, options)

  # add index sort order
  option_strings = add_index_sort_order(option_strings, column_names, options)

  column_names.map {|name| quote_column_name(name) + option_strings[name]}
end
remove_column_sql(table_name, *column_names)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 637
def remove_column_sql(table_name, *column_names)
  columns_for_remove(table_name, *column_names).map {|column_name| "DROP #{column_name}" }
end
remove_index_sql(table_name, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 647
def remove_index_sql(table_name, options = {})
  index_name = index_name_for_remove(table_name, options)
  "DROP INDEX #{index_name}"
end
remove_timestamps_sql(table_name)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 656
def remove_timestamps_sql(table_name)
  [remove_column_sql(table_name, :updated_at), remove_column_sql(table_name, :created_at)]
end
rename_column_sql(table_name, column_name, new_column_name)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 621
def rename_column_sql(table_name, column_name, new_column_name)
  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 = "CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}"
  add_column_options!(rename_column_sql, options)
  rename_column_sql
end
translate_exception(exception, message)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 586
def translate_exception(exception, message)
  case error_number(exception)
  when 1062
    RecordNotUnique.new(message, exception)
  when 1452
    InvalidForeignKey.new(message, exception)
  else
    super
  end
end