class ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter

Parent:
ActiveRecord::ConnectionAdapters::AbstractAdapter
Included modules:
ActiveRecord::ConnectionAdapters::MySQL::ColumnDumper

Constants

CHARSETS_OF_4BYTES_MAXLEN
INDEX_TYPES
INDEX_USINGS
NATIVE_DATABASE_TYPES

Public Class Methods

emulate_booleans() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 38
class_attribute :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
new(connection, logger, connection_options, config) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 65
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 (#{version_string}) is too old. Active Record supports MySQL >= 5.0."
  end
end

Public Instance Methods

begin_db_transaction() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 228
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 232
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) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 616
def case_sensitive_comparison(table, attribute, column, value)
  if !value.nil? && column.collation && !column.case_sensitive?
    table[attribute].eq(Arel::Nodes::Bin.new(Arel::Nodes::BindParam.new))
  else
    super
  end
end
charset() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 300
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 198
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 305
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 279
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 295
def current_database
  select_value 'SELECT DATABASE() as db'
end
data_source_exists?(table_name) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 347
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 = #{schema} AND table_name = #{name}"

  select_values(sql, 'SCHEMA').any?
end
data_sources() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 325
def data_sources
  sql = "SELECT table_name FROM information_schema.tables "
  sql << "WHERE table_schema = DATABASE()"

  select_values(sql, 'SCHEMA')
end
drop_table(table_name, options = {}) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 465
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 257
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 217
def execute(sql, name = nil)
  log(sql, name) { @connection.query(sql) }
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 207
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 515
      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 = #{schema}
            AND fk.table_name = #{name}
            AND rc.table_name = #{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 160
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 156
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 265
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 469
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) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 445
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 595
def show_variable(name)
  select_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 644
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 144
def supports_advisory_locks?
  true
end
supports_datetime_with_precision?() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 136
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 120
def supports_explain?
  true
end
supports_foreign_keys?() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 128
def supports_foreign_keys?
  true
end
supports_index_sort_order?() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 112
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 124
def supports_indexes_in_create?
  true
end
supports_migrations?() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 92
def supports_migrations?
  true
end

Returns true, since this connection adapter supports migrations.

supports_primary_key?() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 96
def supports_primary_key?
  true
end
supports_statement_cache?() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 106
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 116
def supports_transaction_isolation?
  true
end
supports_views?() Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 132
def supports_views?
  true
end
table_exists?(table_name) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 336
      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) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 332
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) Show source
# 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

Maps logical Rails types to MySQL-specific data types.

Calls superclass method
valid_type?(type) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 648
def valid_type?(type)
  !native_database_types[type].nil?
end

Protected Instance Methods

add_column_sql(table_name, column_name, type, options = {}) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 748
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) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 716
def add_index_length(quoted_columns, **options)
  if length = options[:length]
    case length
    when Hash
      length = length.symbolize_keys
      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 = {}) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 792
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) Show source
# 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 = {}) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 803
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 = {}) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 754
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) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 704
def extract_precision(sql_type)
  if /time/ === sql_type
    super || 0
  else
    super
  end
end
Calls superclass method
fetch_type_metadata(sql_type, extra = "") Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 712
def fetch_type_metadata(sql_type, extra = "")
  MySQL::TypeMetadata.new(super(sql_type), extra: extra, strict: strict_mode?)
end
remove_column_sql(table_name, column_name, type = nil, options = {}) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 784
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) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 788
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 = {}) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 798
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 = {}) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 807
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) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 770
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) Show source
# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 735
def translate_exception(exception, message)
  case error_number(exception)
  when 1062
    RecordNotUnique.new(message)
  when 1452
    InvalidForeignKey.new(message)
  when 1406
    ValueTooLong.new(message)
  else
    super
  end
end

© 2004–2018 David Heinemeier Hansson
Licensed under the MIT License.