module ActiveRecord::ConnectionAdapters

Constants

ER_CANNOT_ADD_FOREIGN
ER_CANNOT_CREATE_TABLE
ER_DATA_TOO_LONG
ER_DO_NOT_HAVE_DEFAULT
ER_DUP_ENTRY: See dev.mysql.com/doc/refman/5.7/en/error-messages-server.html
ER_LOCK_DEADLOCK
ER_NOT_NULL_VIOLATION
ER_NO_REFERENCED_ROW_2
ER_OUT_OF_RANGE

Public Class Methods

new(connection, logger, connection_options, config) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 68
def initialize(connection, logger, connection_options, config)
  super(connection, logger, config)

  @statements = StatementPool.new(self.class.type_cast_config_to_integer(config[:statement_limit]))

  if version < "5.1.10"
    raise "Your version of MySQL (#{version_string}) is too old. Active Record supports MySQL >= 5.1.10."
  end
end

Calls superclass method

Public Instance Methods

begin_db_transaction() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 226
def begin_db_transaction
  execute "BEGIN"
end

begin_isolated_db_transaction(isolation) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 230
def begin_isolated_db_transaction(isolation)
  execute "SET TRANSACTION ISOLATION LEVEL #{transaction_isolation_levels.fetch(isolation)}"
  begin_db_transaction
end

charset() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 298
def charset
  show_variable "character_set_database"
end

Returns the database character set.

clear_cache!() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 192
def clear_cache!
  reload_type_map
  @statements.clear
end

Clears the prepared statements cache.

collation() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 303
def collation
  show_variable "collation_database"
end

Returns the database collation strategy.

create_database(name, options = {}) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 277
def create_database(name, options = {})
  if options[:collation]
    execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET #{quote_table_name(options[:charset] || 'utf8')} COLLATE #{quote_table_name(options[:collation])}"
  else
    execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET #{quote_table_name(options[:charset] || 'utf8')}"
  end
end

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

current_database() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 293
def current_database
  query_value("SELECT database()", "SCHEMA")
end

drop_table(table_name, options = {}) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 405
def drop_table(table_name, options = {})
  execute "DROP#{' TEMPORARY' if options[:temporary]} TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_table_name(table_name)}#{' CASCADE' if options[:force] == :cascade}"
end

Drops a table from the database.

:force: Set to :cascade to drop dependent objects as well. Defaults to false.
:if_exists: Set to true to only drop the table if it exists. Defaults to false.
:temporary: Set to true to drop temporary table. Defaults to false.

Although this command ignores most options and the block if one is given, it can be helpful to provide these in a migration's change method so it can be reverted. In that case, options and the block will be used by create_table.

empty_insert_statement_value() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 255
def empty_insert_statement_value
  "VALUES ()"
end

execute(sql, name = nil) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 211
def execute(sql, name = nil)
  log(sql, name) do
    ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
      @connection.query(sql)
    end
  end
end

Executes the SQL statement in the context of this connection.

explain(arel, binds = []) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 201
def explain(arel, binds = [])
  sql     = "EXPLAIN #{to_sql(arel, binds)}"
  start   = Time.now
  result  = exec_query(sql, "EXPLAIN", binds)
  elapsed = Time.now - start

  MySQL::ExplainPrettyPrinter.new.pp(result, elapsed)
end

foreign_keys(table_name) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 455
      def foreign_keys(table_name)
        raise ArgumentError unless table_name.present?

        scope = quoted_scope(table_name)

        fk_info = exec_query("          SELECT fk.referenced_table_name AS 'to_table',
                 fk.referenced_column_name AS 'primary_key',
                 fk.column_name AS 'column',
                 fk.constraint_name AS 'name',
                 rc.update_rule AS 'on_update',
                 rc.delete_rule AS 'on_delete'
          FROM information_schema.referential_constraints rc
          JOIN information_schema.key_column_usage fk
          USING (constraint_schema, constraint_name)
          WHERE fk.referenced_column_name IS NOT NULL
            AND fk.table_schema = #{scope[:schema]}
            AND fk.table_name = #{scope[:name]}
            AND rc.constraint_schema = #{scope[:schema]}
            AND rc.table_name = #{scope[:name]}
".strip_heredoc, "SCHEMA")

        fk_info.map do |row|
          options = {
            column: row["column"],
            name: row["name"],
            primary_key: row["primary_key"]
          }

          options[:on_update] = extract_foreign_key_action(row["on_update"])
          options[:on_delete] = extract_foreign_key_action(row["on_delete"])

          ForeignKeyDefinition.new(table_name, row["to_table"], options)
        end
      end

index_algorithms() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 154
def index_algorithms
  { default: "ALGORITHM = DEFAULT", copy: "ALGORITHM = COPY", inplace: "ALGORITHM = INPLACE" }
end

native_database_types() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 150
def native_database_types
  NATIVE_DATABASE_TYPES
end

recreate_database(name, options = {}) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 263
def recreate_database(name, options = {})
  drop_database(name)
  sql = create_database(name, options)
  reconnect!
  sql
end

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

rename_index(table_name, old_name, new_name) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 409
def rename_index(table_name, old_name, new_name)
  if supports_rename_index?
    validate_index_length!(table_name, new_name)

    execute "ALTER TABLE #{quote_table_name(table_name)} RENAME INDEX #{quote_table_name(old_name)} TO #{quote_table_name(new_name)}"
  else
    super
  end
end

Calls superclass method

rename_table(table_name, new_name) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 385
def rename_table(table_name, new_name)
  execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
  rename_table_indexes(table_name, new_name)
end

Renames a table.

Example:

rename_table('octopuses', 'octopi')

show_variable(name) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 537
def show_variable(name)
  query_value("SELECT @@#{name}", "SCHEMA")
rescue ActiveRecord::StatementInvalid
  nil
end

SHOW VARIABLES LIKE 'name'

strict_mode?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 586
def strict_mode?
  self.class.type_cast_config_to_boolean(@config.fetch(:strict, true))
end

supports_advisory_locks?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 138
def supports_advisory_locks?
  true
end

supports_datetime_with_precision?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 122
def supports_datetime_with_precision?
  if mariadb?
    version >= "5.3.0"
  else
    version >= "5.6.4"
  end
end

supports_explain?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 106
def supports_explain?
  true
end

supports_foreign_keys?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 114
def supports_foreign_keys?
  true
end

supports_index_sort_order?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 98
def supports_index_sort_order?
  true
end

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

supports_indexes_in_create?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 110
def supports_indexes_in_create?
  true
end

supports_statement_cache?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 92
def supports_statement_cache?
  true
end

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

supports_transaction_isolation?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 102
def supports_transaction_isolation?
  true
end

supports_views?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 118
def supports_views?
  true
end

supports_virtual_columns?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 130
def supports_virtual_columns?
  if mariadb?
    version >= "5.2.0"
  else
    version >= "5.7.5"
  end
end

truncate(table_name, name = nil) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 307
def truncate(table_name, name = nil)
  execute "TRUNCATE TABLE #{quote_table_name(table_name)}", name
end