4.38.0.txt

doc/release_notes/4.38.0.txt
Last Update: 2016-09-01 11:38:43 -0700

New Features

  • Sequel::SQL::NumericMethods#coerce has been added, which adds support for ruby's coercion protocol when performing numeric operations. Previously, Sequel supported code like:

    Sequel.expr{a - 1}

    This is because a in this case returns a Sequel::SQL::Indentifier, which defines #- to return a Sequel::SQL::NumericExpression. By supporting coerce, the following code now also works:

    Sequel.expr{1 - a}

    This is because Integer#- calls coerce on the argument if it is defined (ruby's coercion protocol). Previously, you had to handle this differently, using something like:

    Sequel.expr(1) - a
    # or
    Sequel.-(1, a)
  • Sequel now supports the ** operator for exponentiation on expressions, similar to the +, -, *, and / operators. Sequel uses the database power function to implement this by default on the databases that support it (most of them). On Access, it uses the ^ operator, on Derby it is emulated using a combination of exp/ln (with some loss of precision). SQLite doesn't support a power function at all, but Sequel emulates it using multiplication for known integer exponents.

  • Sequel::SQLTime.date= has been added, which allows you to set the date used for Sequel::SQLTime instances. Sequel::SQLTime is a subclass of Time that is literalized using only the time components, and is the ruby class used to store values of database time columns on most adapters. Sequel::SQLTime defaults to using the current date, but you can now set a specific date, for more consistency with some drivers (Mysql2 uses 2000-01-01, tiny_tds uses 1900-01-01).

  • The postgres adapter now supports a :driver_options option when using the pg driver, which is passed directly to pg. This can be used to specify a client SSL certificate or to specify the certificate authority root certificate when using :sslmode=>'verify-full'.

Other Improvements

  • Sequel no longer uses after_commit/rollback database hooks by default if the after_commit/after_rollback model methods are not overridden. This provides a performance speedup, but the main benefit is that it no longer causes memory issues when saving a large number of model instances in a single transaction, and it also works with prepared transactions/2 phase commit. You can still set use_after_commit_rollback= manually to force the after_commit/rollback setting.

    Note that Sequel 5 will move after_commit/rollback model hooks to a plugin, and the default and recommended approach will be to use the database after_commit/rollback hooks in the after_save or similar model hooks.

Backwards Compatibility

  • The Sequel::Model use_after_commit_rollback class and instance methods now return nil by default instead of true. nil now indicates the default behavior of checking whether the appropriate model hook has been defined, and only adding a database hook if so.