does not have TIME data type.

Speed up Hash#transform_keys using Hash#each_key

See https://gist.github.com/3007749 for justification

fix bug in limit of enum columns of mysql

Closes #6432

Fixes #6825, adds tests covering cases and error possibilities

Fixes #6825, adds tests covering cases and error possibilities, also changes SQLite3 driver to correctly generate a time column instead of datetime

Pull request #6856, merged in 52f6e476.
[ci skip]

Fix wrong testcase for db:test:prepare, and wrong environment in AR rake task.

Add polymorphic option to model generator

For instance,

    $ rails g model Product supplier:references{polymorphic}

generate model with `belongs_to :supplier, polymorphic: true` association and appropriate migration.

Address test_basic_model test error with Oracle enhanced adapter

which ids start from 1000 as a default.

For instance,

    $ rails g model Product supplier:references{polymorphic}

generate model with `belongs_to :supplier, polymorphic: true` association and appropriate migration.

Also fix model_generator_test.rb#L196 and #L201

Guide update for Async ActionMailer

Since we're dealing with a new array instance, it's safe to use map! and
we avoid an extra array object.

Also remove the symbolize_keys! from AttributeMethodMatcher, since it's
an internal class that always receives symbol keys from the prefix/suffix
methods implementations.

Since we're not directly requiring the reverse_merge extension, we can
avoid another hash creation by using default_hash.merge! instead.

There's no need to create two extra hashes with options.merge(another_hash),
with the goal of setting only one value, so lets just set it.

Also refactor validates_each to use _merge_attributes, like other
validates_* helpers do.

Also simplify I18n logic for Array#to_sentence, doing only one lookup
for all keys and using merge!, instead of one lookup for each option key.

Setup each test with default ActiveRecord timezone settings to ensure ea...

Setup each test with default ActiveRecord timezone settings to ensure each test starts with a clean slate.
Fixes #6867.

AS::Callbacks: deprecate monkey patch code

:update_details method no more exists on @lookup_context

Async actionmailer

Deprecate usage of filter object with #before and #after
methods as around callback

the method has gone in this commit: 119e9e2d

Try to use more destructive methods on *args when applicable, to avoid
creating new objects.

exists?(false) returns false

Fix build issue with postgresql.

Missing require breaks Time.=== when selectively loading ActiveSupport core_exts in 3.2.4+

If you selectively require core_exts (e.g., require
'active_support/core_ext/string'), it is possible for
'active_support/core_ext/time/calculations' to be required when
`ActiveSupport::TimeWithZone` is not available. If this happens, the next call
to Time.=== will fail with a NameError.

Refactor and improve database tasks.