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Included Modules

Constants

CR_SERVER_GONE_ERROR = 2006
 
CR_SERVER_LOST = 2013
 
EMULATE_BOOLEANS_TRUE = { emulate_booleans: true }.freeze
 
ER_CANNOT_ADD_FOREIGN = 1215
 
ER_CANNOT_CREATE_TABLE = 1005
 
ER_CHECK_CONSTRAINT_VIOLATED = 3819
 
ER_CLIENT_INTERACTION_TIMEOUT = 4031
 
ER_CONNECTION_KILLED = 1927
 
ER_CONSTRAINT_FAILED = 4025
 
ER_DATA_TOO_LONG = 1406
 
ER_DB_CREATE_EXISTS = 1007
 

See dev.mysql.com/doc/mysql-errors/en/server-error-reference.html
ER_DO_NOT_HAVE_DEFAULT = 1364
 
ER_DUP_ENTRY = 1062
 
ER_FILSORT_ABORT = 1028
 
ER_FK_INCOMPATIBLE_COLUMNS = 3780
 
ER_LOCK_DEADLOCK = 1213
 
ER_LOCK_WAIT_TIMEOUT = 1205
 
ER_NOT_NULL_VIOLATION = 1048
 
ER_NO_DB_ERROR = 1046
 
ER_NO_REFERENCED_ROW = 1216
 
ER_NO_REFERENCED_ROW_2 = 1452
 
ER_OUT_OF_RANGE = 1264
 
ER_QUERY_INTERRUPTED = 1317
 
ER_QUERY_TIMEOUT = 3024
 
ER_ROW_IS_REFERENCED = 1217
 
ER_ROW_IS_REFERENCED_2 = 1451
 
ER_SERVER_SHUTDOWN = 1053
 
EXTENDED_TYPE_MAPS = Concurrent::Map.new
 
MARIADB_DEFAULT_ESCAPES = { "0" => "\0", "b" => "\b", "n" => "\n", "r" => "\r", "t" => "\t", "Z" => "\x1A", "'" => "'", '"' => '"', "\\" => "\\" }.freeze
 

Escape sequences MariaDB writes into the column defaults it reports.
NATIVE_DATABASE_TYPES = { # rubocop:disable Style/MutableConstant primary_key: "bigint auto_increment PRIMARY KEY", string: { name: "varchar", limit: 255 }, text: { name: "text" }, integer: { name: "int", limit: 4 }, bigint: { name: "bigint" }, float: { name: "float", limit: 24 }, decimal: { name: "decimal" }, datetime: { name: "datetime" }, timestamp: { name: "timestamp" }, time: { name: "time" }, date: { name: "date" }, binary: { name: "blob" }, blob: { name: "blob" }, boolean: { name: "boolean" }, json: { name: "json" }, }
 

Class Public methods

dbconsole(config, options = {})

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 63
def dbconsole(config, options = {})
  mysql_config = config.configuration_hash

  args = {
    host: "--host",
    port: "--port",
    socket: "--socket",
    username: "--user",
    encoding: "--default-character-set",
    sslca: "--ssl-ca",
    sslcert: "--ssl-cert",
    sslcapath: "--ssl-capath",
    sslcipher: "--ssl-cipher",
    sslkey: "--ssl-key",
    ssl_mode: "--ssl-mode"
  }.filter_map { |opt, arg| "#{arg}=#{mysql_config[opt]}" if mysql_config[opt] }

  if mysql_config[:password] && options[:include_password]
    args << "--password=#{mysql_config[:password]}"
  elsif mysql_config[:password] && !mysql_config[:password].to_s.empty?
    args << "-p"
  end

  args << config.database

  find_cmd_and_exec(ActiveRecord.database_cli[:mysql], *args)
end

emulate_booleans

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

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 29
class_attribute :emulate_booleans, default: true

Instance Public methods

charset()

Returns the database character set.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 350
def charset
  show_variable "character_set_database"
end

check_constraints(table_name)

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 524
def check_constraints(table_name)
  result = fetch_check_constraints(Array(table_name).map(&:to_s))
  table_name.is_a?(Array) ? result : result[table_name.to_s]
end

collation()

Returns the database collation strategy.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 355
def collation
  show_variable "collation_database"
end

create_database(name, options = {})

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

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 325
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

current_database()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 345
def current_database
  query_value("SELECT database()")
end

drop_table(*table_names, **options)

Drops a table or tables 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 except if you provide more than one table which is not supported.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 408
def drop_table(*table_names, **options)
  table_names.each { |table_name| schema_cache.clear_data_source_cache!(table_name.to_s) }
  execute drop_table_sql(*table_names, **options)
end

foreign_keys(table_name)

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 519
def foreign_keys(table_name)
  result = fetch_foreign_keys(Array(table_name).map(&:to_s))
  table_name.is_a?(Array) ? result : result[table_name.to_s]
end

index_algorithms()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 209
def index_algorithms
  {
    default: "ALGORITHM = DEFAULT",
    copy:    "ALGORITHM = COPY",
    inplace: "ALGORITHM = INPLACE",
    instant: "ALGORITHM = INSTANT",
  }
end

lock_options()

Returns the available lock options for MySQL DDL operations.

MySQL supports the following lock modes:

  • :default - Let MySQL decide the lock level.

  • :none - Allow concurrent reads and writes (online DDL).

  • :shared - Allow concurrent reads but block writes.

  • :exclusive - Block all concurrent reads and writes.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 225
def lock_options
  {
    default:   "LOCK = DEFAULT",
    none:      "LOCK = NONE",
    shared:    "LOCK = SHARED",
    exclusive: "LOCK = EXCLUSIVE",
  }
end

quote_string(string)

Quotes strings for use in SQL input.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 657
def quote_string(string)
  with_raw_connection(allow_retry: true, materialize_transactions: false) do |connection|
    connection.escape(string)
  end
end

recreate_database(name, options = {})

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

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 311
def recreate_database(name, options = {})
  drop_database(name)
  sql = create_database(name, options)
  reconnect!
  sql
end

rename_index(table_name, old_name, new_name)

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 413
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

rename_table(table_name, new_name, **options)

Renames a table.

Example:

rename_table('octopuses', 'octopi')

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 385
def rename_table(table_name, new_name, **options)
  validate_table_length!(new_name) unless options[:_uses_legacy_table_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, **options)
end

show_variable(name)

SHOW VARIABLES LIKE ‘name’

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 530
def show_variable(name)
  query_value("SELECT @@#{name}")
rescue ActiveRecord::StatementInvalid
  nil
end

strict_mode?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 571
      def strict_mode?
        if @config.key?(:strict) && !@strict_mode_deprecation_warned
          @strict_mode_deprecation_warned = true
          ActiveRecord.deprecator.warn(<<~MSG.squish)
            The `strict` option in database configurations is deprecated and
            will be removed in Rails 9.0. Use `variables: { sql_mode: "..." }`
            to configure sql_mode directly instead.
          MSG
        end

        self.class.type_cast_config_to_boolean(@config.fetch(:strict, true))
      end

supports_advisory_locks?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 171
def supports_advisory_locks?
  true
end

supports_bulk_alter?()

Source: show | on GitHub 

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

supports_check_constraints?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 138
def supports_check_constraints?
  if mariadb?
    database_version >= "10.3.10" || (database_version < "10.3" && database_version >= "10.2.22")
  else
    database_version >= "8.0.16"
  end
end

supports_common_table_expressions?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 163
def supports_common_table_expressions?
  if mariadb?
    database_version >= "10.2.1"
  else
    database_version >= "8.0.1"
  end
end

supports_datetime_with_precision?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 150
def supports_datetime_with_precision?
  true
end

supports_disabling_indexes?()

See dev.mysql.com/doc/refman/8.0/en/invisible-indexes.html for more details on MySQL feature. See mariadb.com/kb/en/ignored-indexes/ for more details on the MariaDB feature.

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 193
def supports_disabling_indexes?
  if mariadb?
    database_version >= "10.6.0"
  else
    database_version >= "8.0.0"
  end
end

supports_explain?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 126
def supports_explain?
  true
end

supports_expression_index?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 114
def supports_expression_index?
  !mariadb? && database_version >= "8.0.13"
end

supports_foreign_keys?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 134
def supports_foreign_keys?
  true
end

supports_index_sort_order?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 110
def supports_index_sort_order?
  mariadb? ? database_version >= "10.8.1" : database_version >= "8.0.1"
end

supports_indexes_in_create?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 130
def supports_indexes_in_create?
  true
end

supports_insert_on_duplicate_skip?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 175
def supports_insert_on_duplicate_skip?
  true
end

supports_insert_on_duplicate_update?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 179
def supports_insert_on_duplicate_update?
  true
end

supports_insert_returning?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 183
def supports_insert_returning?
  mariadb? && database_version >= "10.5.0"
end

supports_optimizer_hints?()

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

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 159
def supports_optimizer_hints?
  !mariadb? && database_version >= "5.7.7"
end

supports_restart_db_transaction?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 122
def supports_restart_db_transaction?
  true
end

supports_transaction_isolation?()

Source: show | on GitHub 

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

supports_views?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 146
def supports_views?
  true
end

supports_virtual_columns?()

Source: show | on GitHub 

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 154
def supports_virtual_columns?
  mariadb? || database_version >= "5.7.5"
end