class ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter

Parent:: ActiveRecord::ConnectionAdapters::AbstractAdapter

Constants

ER_CANNOT_ADD_FOREIGN
ER_CANNOT_CREATE_TABLE
ER_DATA_TOO_LONG
ER_DB_CREATE_EXISTS: See dev.mysql.com/doc/mysql-errors/en/server-error-reference.html
ER_DO_NOT_HAVE_DEFAULT
ER_DUP_ENTRY
ER_FILSORT_ABORT
ER_FK_INCOMPATIBLE_COLUMNS
ER_LOCK_DEADLOCK
ER_LOCK_WAIT_TIMEOUT
ER_NOT_NULL_VIOLATION
ER_NO_REFERENCED_ROW
ER_NO_REFERENCED_ROW_2
ER_OUT_OF_RANGE
ER_QUERY_INTERRUPTED
ER_QUERY_TIMEOUT
ER_ROW_IS_REFERENCED
ER_ROW_IS_REFERENCED_2
NATIVE_DATABASE_TYPES

Public Class Methods

emulate_booleans() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 27
class_attribute :emulate_booleans, default: true

By default, the Mysql2Adapter will consider all columns of type tinyint(1) as boolean. If you wish to disable this emulation you can add the following line to your application.rb file:

ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans = false

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

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 53
def initialize(connection, logger, connection_options, config)
  super(connection, logger, config)
end

Calls superclass method ActiveRecord::ConnectionAdapters::QueryCache::new

Public Instance Methods

begin_db_transaction() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 218
def begin_db_transaction
  execute("BEGIN", "TRANSACTION")
end

begin_isolated_db_transaction(isolation) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 222
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 282
def charset
  show_variable "character_set_database"
end

Returns the database character set.

check_constraints(table_name) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 426
      def check_constraints(table_name)
        if supports_check_constraints?
          scope = quoted_scope(table_name)

          chk_info = exec_query(<<~SQL, "SCHEMA")
            SELECT cc.constraint_name AS 'name',
                  cc.check_clause AS 'expression'
            FROM information_schema.check_constraints cc
            JOIN information_schema.table_constraints tc
            USING (constraint_schema, constraint_name)
            WHERE tc.table_schema = #{scope[:schema]}
              AND tc.table_name = #{scope[:name]}
              AND cc.constraint_schema = #{scope[:schema]}
          SQL

          chk_info.map do |row|
            options = {
              name: row["name"]
            }
            expression = row["expression"]
            expression = expression[1..-2] unless mariadb? # remove parentheses added by mysql
            CheckConstraintDefinition.new(table_name, expression, options)
          end
        else
          raise NotImplementedError
        end
      end

collation() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 287
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 257
def create_database(name, options = {})
  if options[:collation]
    execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT COLLATE #{quote_table_name(options[:collation])}"
  elsif options[:charset]
    execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET #{quote_table_name(options[:charset])}"
  elsif row_format_dynamic_by_default?
    execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET `utf8mb4`"
  else
    raise "Configure a supported :charset and ensure innodb_large_prefix is enabled to support indexes on varchar(255) string columns."
  end
end

Create a new MySQL database with optional :charset and :collation. Charset defaults to utf8mb4.

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 277
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 334
def drop_table(table_name, **options)
  schema_cache.clear_data_source_cache!(table_name.to_s)
  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(primary_key = nil) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 235
def empty_insert_statement_value(primary_key = nil)
  "VALUES ()"
end

execute(sql, name = nil) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 200
def execute(sql, name = nil)
  materialize_transactions
  mark_transaction_written_if_write(sql)

  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.

foreign_keys(table_name) Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 390
      def foreign_keys(table_name)
        raise ArgumentError unless table_name.present?

        scope = quoted_scope(table_name)

        fk_info = exec_query(<<~SQL, "SCHEMA")
          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]}
        SQL

        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 152
def index_algorithms
  {
    default: "ALGORITHM = DEFAULT",
    copy:    "ALGORITHM = COPY",
    inplace: "ALGORITHM = INPLACE",
    instant: "ALGORITHM = INSTANT",
  }
end

native_database_types() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 148
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 243
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 339
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 312
def rename_table(table_name, new_name)
  schema_cache.clear_data_source_cache!(table_name.to_s)
  schema_cache.clear_data_source_cache!(new_name.to_s)
  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 484
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 535
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 128
def supports_advisory_locks?
  true
end

supports_bulk_alter?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 67
def supports_bulk_alter?
  true
end

supports_check_constraints?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 95
def supports_check_constraints?
  if mariadb?
    database_version >= "10.2.1"
  else
    database_version >= "8.0.16"
  end
end

supports_common_table_expressions?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 120
def supports_common_table_expressions?
  if mariadb?
    database_version >= "10.2.1"
  else
    database_version >= "8.0.1"
  end
end

supports_datetime_with_precision?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 107
def supports_datetime_with_precision?
  mariadb? || database_version >= "5.6.4"
end

supports_explain?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 83
def supports_explain?
  true
end

supports_expression_index?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 75
def supports_expression_index?
  !mariadb? && database_version >= "8.0.13"
end

supports_foreign_keys?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 91
def supports_foreign_keys?
  true
end

supports_index_sort_order?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 71
def supports_index_sort_order?
  !mariadb? && database_version >= "8.0.1"
end

supports_indexes_in_create?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 87
def supports_indexes_in_create?
  true
end

supports_insert_on_duplicate_skip?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 132
def supports_insert_on_duplicate_skip?
  true
end

supports_insert_on_duplicate_update?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 136
def supports_insert_on_duplicate_update?
  true
end

supports_optimizer_hints?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 116
def supports_optimizer_hints?
  !mariadb? && database_version >= "5.7.7"
end

See dev.mysql.com/doc/refman/en/optimizer-hints.html for more details.

supports_transaction_isolation?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 79
def supports_transaction_isolation?
  true
end

supports_views?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 103
def supports_views?
  true
end

supports_virtual_columns?() Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 111
def supports_virtual_columns?
  mariadb? || database_version >= "5.7.5"
end