ANN: Sequel 3.33.0 Released

Sequel is a lightweight database access toolkit for Ruby.

  • Sequel provides thread safety, connection pooling and a concise
    DSL for constructing SQL queries and table schemas.
  • Sequel includes a comprehensive ORM layer for mapping records to
    Ruby objects and handling associated records.
  • Sequel supports advanced database features such as prepared
    statements, bound variables, stored procedures, savepoints,
    two-phase commit, transaction isolation, master/slave
    configurations, and database sharding.
  • Sequel currently has adapters for ADO, Amalgalite, DataObjects,
    DB2, DBI, Firebird, IBM_DB, Informix, JDBC, MySQL, Mysql2, ODBC,
    OpenBase, Oracle, PostgreSQL, SQLite3, Swift, and TinyTDS.

Sequel 3.33.0 has been released and should be available on the gem

= New Features

  • A server_block extension has been added that makes Sequel’s
    sharding support easier to use by scoping database access inside
    the block to a given server/shard:

    Sequel.extension :server_block
    DB.extend Sequel::ServerBlock
    DB.with_server(:shard_1) do
    # All of these will execute against shard_1
    DB[:table].all ‘SOME SQL’

  • An arbitrary_servers extension has been added that extends
    Sequel’s sharding support so that you can use arbitrary
    connection options instead of referencing an existing, predefined

    Sequel.extension :arbitrary_servers
    DB.pool.extend Sequel::ArbitraryServers
    DB[:table].server(:host=>‘foo’, :database=>‘bar’).all

    You can use this extension in conjunction with the server_block

    DB.with_server(:host=>‘foo’, :database=>‘bar’) do
    DB.synchronize do
    # All of these will execute on host foo, database bar
    DB[:table].all ‘SOME SQL’

    The combination of these two extensions makes it pretty easy to
    write a thread-safe Rack middleware that scopes each request
    to an arbitrary database.

  • The sqlite adapter now supports an integer_booleans setting
    for using 1/0 for true/false values, instead of the the ‘t’/‘f’
    values used by default. As SQLite recommends using integers to
    store booleans, converting your existing database and enabling
    this setting is recommended, but for backwards compatibility it
    is set to false. You can convert you existing database by doing
    the following for each table/column that has booleans:

    case(0, :boolean_column))

    The integer_booleans default setting may change in a future
    version of Sequel, so you should set it manually to false if you
    prefer the current default.

  • You can now disable transaction use in migrations, in one of two
    ways. You generally only need to do this if you are using an
    SQL query inside a migration that is specifically not supported
    inside a transaction, such as CREATE INDEX CONCURRENTLY on

    The first way to disable transactions is on a per-migration basis
    by calling the no_transaction method inside the Sequel.migration

    Sequel.migration do
    change do
    # …

    That will make it so that a transaction is not used for that
    particular migration. The second way is passing the
    :use_tranctions=>false option when calling (using
    the API), which will completely disable transactions for all
    migrations during the migrator run.

  • The postgres adapter now respects an :sslmode option when using
    pg as the underlying driver, you can set the value of this option to
    disable, allow, prefer, or require.

  • Database#create_schema and #drop_schema are now defined when
    connecting to PostgreSQL.

  • Database#supports_savepoints_in_prepared_transactions? has been
    added for checking if savepoints are supported inside prepared
    transactions. This is true if both savepoints and prepared
    transactions are both supported, except on MySQL > 5.5.12 (due to
    MySQL bug 64374).

= Other Improvements

  • The mysql and mysql2 adapters now both provide an accurate number
    of rows matched, so Sequel::Model usage on those adapters will now
    raise a NoExistingObject exception by default if you attempt to
    delete or update an instance that no longer exists in the database.

  • Foreign key creation now works correctly without specifying the
    :key option when using MySQL with the InnoDB table engine. InnoDB
    requires that you list the column explicitly, even if you are
    referencing the primary key of the table, so if the :key option is
    not given, the database schema is introspected to find the primary
    key for the table. If you are attempting to create a table with
    a self-referential foreign key, it introspects the generator to
    get the primary key for the table.

  • The sqlite adapter will now return 1/0 stored in boolean columns as
    true/false. It will convert dates stored as Integers/Floats to
    Date objects by assuming they represent the julian date. It will
    convert times stored as Integers/Floats to Sequel::SQLTime objects
    by assuming they represent a number of seconds. It will convert
    datetimes stored as Integers by assuming they represent a unix
    epoch time integer, and datetimes stored as Floats by assuming the
    represent the julian date (with fractional part representing the
    time of day). These changes make Sequel handle SQLite’s
    recommendations for boolean/date/time storage.

  • The instance_hooks plugin’s (before|after)_*_hook methods now return
    self so they can be used in a method chain.

  • The list plugin now automatically adds new entries to the end of the
    list when creating the entries, if the position field is not
    specifically set.

  • An identifier_output_method is now respected in the mysql2 adapter.

  • NaN/Infinity Float values are now quoted correctly for input on
    PostgreSQL, and the postgres adapter correctly handles them on
    retrieval from the database.

  • The :collate column option is now respected when creating tables or
    altering columns on MySQL.

  • You can now force use of the TimestampMigrator when the
    IntegerMigrator would be used by default by calling
    TimestampMigrator.apply or .run.

  • Mock adapter usage with a specific SQL dialect now uses the
    appropriate defaults for quoting identifiers.

  • You can now disable the use of sudo in the rake install/uninstall
    tasks using the SUDO=‘’ environment variable.

  • A very misleading error message has been fixed when attempting
    to constantize an invalid string in the model inflector.

= Backwards Compatibility

  • The sqlite adapter now typecasts columns that SQLite stores as
    INTEGER/REAL. Previously, it only typecasted columns that
    SQLite stored as TEXT/BLOB. For details about SQLite storage, see
    Datatypes In SQLite.

    Any custom type conversion procs used with the sqlite adapter should
    be modified to work with Integer/Float objects in addition to String