edge badge
Namespace
Methods
A
B
C
D
E
F
I
N
R
S
T
V
Constants
CHARSETS_OF_4BYTES_MAXLEN = ["utf8mb4", "utf16", "utf16le", "utf32"]
 
ER_DUP_ENTRY = 1062
 

See dev.mysql.com/doc/refman/5.7/en/error-messages-server.html

ER_NO_REFERENCED_ROW_2 = 1452
 
ER_DATA_TOO_LONG = 1406
 
ER_LOCK_DEADLOCK = 1213
 
Class Public methods
new(connection, logger, connection_options, config)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 66
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 < "5.0.0"
    raise "Your version of MySQL (#{full_version.match(/^\d+\.\d+\.\d+/)[0]}) is too old. Active Record supports MySQL >= 5.0."
  end
end
Instance Public methods
begin_db_transaction()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 229
def begin_db_transaction
  execute "BEGIN"
end
begin_isolated_db_transaction(isolation)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 233
def begin_isolated_db_transaction(isolation)
  execute "SET TRANSACTION ISOLATION LEVEL #{transaction_isolation_levels.fetch(isolation)}"
  begin_db_transaction
end
case_sensitive_comparison(table, attribute, column, value)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 617
def case_sensitive_comparison(table, attribute, column, value)
  if column.collation && !column.case_sensitive?
    table[attribute].eq(Arel::Nodes::Bin.new(Arel::Nodes::BindParam.new))
  else
    super
  end
end
charset()

Returns the database character set.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 301
def charset
  show_variable "character_set_database"
end
clear_cache!()

Clears the prepared statements cache.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 199
def clear_cache!
  reload_type_map
  @statements.clear
end
collation()

Returns the database collation strategy.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 306
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 280
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
current_database()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 296
def current_database
  select_value "SELECT DATABASE() as db"
end
data_source_exists?(table_name)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 348
def data_source_exists?(table_name)
  return false unless table_name.present?

  schema, name = extract_schema_qualified_name(table_name)

  sql = "SELECT table_name FROM information_schema.tables "
  sql << "WHERE table_schema = #{quote(schema)} AND table_name = #{quote(name)}"

  select_values(sql, "SCHEMA").any?
end
data_sources()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 326
def data_sources
  sql = "SELECT table_name FROM information_schema.tables "
  sql << "WHERE table_schema = #{quote(@config[:database])}"

  select_values(sql, "SCHEMA")
end
drop_table(table_name, options = {})

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.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 466
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
empty_insert_statement_value()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 258
def empty_insert_statement_value
  "VALUES ()"
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 218
def execute(sql, name = nil)
  log(sql, name) { @connection.query(sql) }
end
explain(arel, binds = [])
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 208
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)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 516
      def foreign_keys(table_name)
        raise ArgumentError unless table_name.present?

        schema, name = extract_schema_qualified_name(table_name)

        fk_info = select_all("          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.key_column_usage fk
          JOIN information_schema.referential_constraints rc
          USING (constraint_schema, constraint_name)
          WHERE fk.referenced_column_name IS NOT NULL
            AND fk.table_schema = #{quote(schema)}
            AND fk.table_name = #{quote(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()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 161
def index_algorithms
  { default: "ALGORITHM = DEFAULT", copy: "ALGORITHM = COPY", inplace: "ALGORITHM = INPLACE" }
end
native_database_types()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 157
def native_database_types
  NATIVE_DATABASE_TYPES
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 266
def recreate_database(name, options = {})
  drop_database(name)
  sql = create_database(name, options)
  reconnect!
  sql
end
rename_index(table_name, old_name, new_name)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 470
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)

Renames a table.

Example:

rename_table('octopuses', 'octopi')
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 446
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
show_variable(name)

SHOW VARIABLES LIKE 'name'

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 596
def show_variable(name)
  select_value("SELECT @@#{name}", "SCHEMA")
rescue ActiveRecord::StatementInvalid
  nil
end
strict_mode?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 645
def strict_mode?
  self.class.type_cast_config_to_boolean(@config.fetch(:strict, true))
end
supports_advisory_locks?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 145
def supports_advisory_locks?
  true
end
supports_datetime_with_precision?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 137
def supports_datetime_with_precision?
  if mariadb?
    version >= "5.3.0"
  else
    version >= "5.6.4"
  end
end
supports_explain?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 121
def supports_explain?
  true
end
supports_foreign_keys?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 129
def supports_foreign_keys?
  true
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 113
def supports_index_sort_order?
  true
end
supports_indexes_in_create?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 125
def supports_indexes_in_create?
  true
end
supports_migrations?()

Returns true, since this connection adapter supports migrations.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 93
def supports_migrations?
  true
end
supports_primary_key?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 97
def supports_primary_key?
  true
end
supports_statement_cache?()

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

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 107
def supports_statement_cache?
  true
end
supports_transaction_isolation?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 117
def supports_transaction_isolation?
  true
end
supports_views?()
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 133
def supports_views?
  true
end
table_exists?(table_name)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 337
      def table_exists?(table_name)
        # Update lib/active_record/internal_metadata.rb when this gets removed
        ActiveSupport::Deprecation.warn("          #table_exists? currently checks both tables and views.
          This behavior is deprecated and will be changed with Rails 5.1 to only check tables.
          Use #data_source_exists? instead.
".squish)

        data_source_exists?(table_name)
      end
truncate(table_name, name = nil)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 333
def truncate(table_name, name = nil)
  execute "TRUNCATE TABLE #{quote_table_name(table_name)}", name
end
type_to_sql(type, limit = nil, precision = nil, scale = nil, unsigned = nil)

Maps logical Rails types to MySQL-specific data types.

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 572
def type_to_sql(type, limit = nil, precision = nil, scale = nil, unsigned = nil)
  sql =            case type.to_s
    when "integer"
      integer_to_sql(limit)
    when "text"
      text_to_sql(limit)
    when "blob"
      binary_to_sql(limit)
    when "binary"
      if (0..0xfff) === limit
        "varbinary(#{limit})"
      else
        binary_to_sql(limit)
      end
    else
      super(type, limit, precision, scale)
    end

  sql << " unsigned" if unsigned && type != :primary_key
  sql
end
valid_type?(type)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 649
def valid_type?(type)
  !native_database_types[type].nil?
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 756
def add_column_sql(table_name, column_name, type, options = {})
  td = create_table_definition(table_name)
  cd = td.new_column_definition(column_name, type, options)
  schema_creation.accept(AddColumnDefinition.new(cd))
end
add_index_length(quoted_columns, **options)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 717
def add_index_length(quoted_columns, **options)
  if length = options[:length]
    case length
    when Hash
      quoted_columns.each { |name, column| column << "(#{length[name]})" if length[name].present? }
    when Integer
      quoted_columns.each { |name, column| column << "(#{length})" }
    end
  end

  quoted_columns
end
add_index_sql(table_name, column_name, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 800
def add_index_sql(table_name, column_name, options = {})
  index_name, index_type, index_columns, _, index_algorithm, index_using = add_index_options(table_name, column_name, options)
  index_algorithm[0, 0] = ", " if index_algorithm.present?
  "ADD #{index_type} INDEX #{quote_column_name(index_name)} #{index_using} (#{index_columns})#{index_algorithm}"
end
add_options_for_index_columns(quoted_columns, **options)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 730
def add_options_for_index_columns(quoted_columns, **options)
  quoted_columns = add_index_length(quoted_columns, options)
  super
end
add_timestamps_sql(table_name, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 811
def add_timestamps_sql(table_name, options = {})
  [add_column_sql(table_name, :created_at, :datetime, options), add_column_sql(table_name, :updated_at, :datetime, options)]
end
change_column_sql(table_name, column_name, type, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 762
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

  td = create_table_definition(table_name)
  cd = td.new_column_definition(column.name, type, options)
  schema_creation.accept(ChangeColumnDefinition.new(cd, column.name))
end
extract_precision(sql_type)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 705
def extract_precision(sql_type)
  if /time/ === sql_type
    super || 0
  else
    super
  end
end
fetch_type_metadata(sql_type, extra = "")
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 713
def fetch_type_metadata(sql_type, extra = "")
  MySQL::TypeMetadata.new(super(sql_type), extra: extra)
end
remove_column_sql(table_name, column_name, type = nil, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 792
def remove_column_sql(table_name, column_name, type = nil, options = {})
  "DROP #{quote_column_name(column_name)}"
end
remove_columns_sql(table_name, *column_names)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 796
def remove_columns_sql(table_name, *column_names)
  column_names.map { |column_name| remove_column_sql(table_name, column_name) }
end
remove_index_sql(table_name, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 806
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, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 815
def remove_timestamps_sql(table_name, options = {})
  [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 778
def rename_column_sql(table_name, column_name, new_column_name)
  column  = column_for(table_name, column_name)
  options = {
    default: column.default,
    null: column.null,
    auto_increment: column.auto_increment?
  }

  current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'", "SCHEMA")["Type"]
  td = create_table_definition(table_name)
  cd = td.new_column_definition(new_column_name, current_type, options)
  schema_creation.accept(ChangeColumnDefinition.new(cd, column.name))
end
translate_exception(exception, message)
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 741
def translate_exception(exception, message)
  case error_number(exception)
  when ER_DUP_ENTRY
    RecordNotUnique.new(message)
  when ER_NO_REFERENCED_ROW_2
    InvalidForeignKey.new(message)
  when ER_DATA_TOO_LONG
    ValueTooLong.new(message)
  when ER_LOCK_DEADLOCK
    Deadlocked.new(message)
  else
    super
  end
end