ActiveRecord::Relation::Merger's filter_binds method does not filter out bind
variables when one of the attribute nodes has a string name, but the other has
a symbol name, even when those names are actually equal.

This can result in there being more bind variables than placeholders in the
generated SQL.  This is particularly an issue for PostgreSQL, where this is
treated as an error.

This patch changes the filter_binds method to make it convert both attribute
names to strings before comparing.

This is a regression 4.0 -> 4.1 fix.
In 4.1.0 Relation#join is delegated to Arel#SelectManager.
In 4.0 series it is delegated to Array#join

This patch puts back the behaviour of 4.0

Changed the call to a scope block to be evaluated with instance_eval.
The result is that ScopeRegistry can use the actual class instead of base_class when
caching scopes so queries made by classes with a common ancestor won't leak scopes.

See #9869 and #9929.

The problem arises from the following example:

    class Project < ActiveRecord::Base
      scope :completed, -> { where completed: true }
    end

    class MajorProject < Project
    end

When calling:

    MajorProject.where(tasks_count: 10).completed

This expands to:

    MajorProject.where(tasks_count: 10).scoping {
      MajorProject.completed
    }

However the lambda for the `completed` scope is defined on Project. This
means that when it is called, `self` is Project rather than
MajorProject. So it expands to:

    MajorProject.where(tasks_count: 10).scoping {
      Project.where(completed: true)
    }

Since the scoping was applied on MajorProject, and not Project, this
fails to apply the tasks_count condition.

The solution is to make scoping apply across STI classes. I am slightly
concerned about the possible side-effects of this, but no tests fail and
it seems ok. I guess we'll see.

It doesn't serve much purpose now that ActiveRecord::Base.all returns a
Relation.

The code is moved to active_record_deprecated_finders.

Don't use this:

    scope :red, where(color: 'red')
    default_scope where(color: 'red')

Use this:

    scope :red, -> { where(color: 'red') }
    default_scope { where(color: 'red') }

The former has numerous issues. It is a common newbie gotcha to do
the following:

    scope :recent, where(published_at: Time.now - 2.weeks)

Or a more subtle variant:

    scope :recent, -> { where(published_at: Time.now - 2.weeks) }
    scope :recent_red, recent.where(color: 'red')

Eager scopes are also very complex to implement within Active
Record, and there are still bugs. For example, the following does
not do what you expect:

    scope :remove_conditions, except(:where)
    where(...).remove_conditions # => still has conditions

Revert "Deprecate defining scopes with a callable (lambda, proc, etc) via the scope class method. Just define a class method yourself instead."

This reverts commit f0e198bf.

Conflicts:

	activerecord/test/models/post.rb

Deprecate defining scopes with a callable (lambda, proc, etc) via the scope class method. Just define a class method yourself instead.

Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

Let AssociationCollection#find use #scoped to do its finding. Note that I am removing test_polymorphic_has_many_going_through_join_model_with_disabled_include, since this specifies different behaviour for an association than for a regular scope. It seems reasonable to expect scopes and association proxies to behave in roughly the same way rather than having subtle differences.

Add some tests for functionality in JoinAssociation which already exists but was previously untested

Add support for nested through associations in JoinAssociation. Hence Foo.joins(:bar) will work for through associations. There is some duplicated code now, which will be refactored.

Refactoring JoinDependency and friends. This improves the code (IMO) including adding some explanatory comments, but more importantly structures it in such a way as to allow a JoinAssociation to produce an arbitrary number of actual joins, which will be necessary for nested has many through support. Also added 3 tests covering functionality which existed but was not previously covered.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@9084 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8735 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8657 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

 Ticket #1874 - Firebird adapter
 r3107@asus:  jeremy | 2005-11-16 00:06:14 -0800
 quote column aliases
 r3108@asus:  jeremy | 2005-11-16 00:08:12 -0800
 quote columns in construct_conditions_from_arguments.  update sequence_name docs.  introduce prefetched primary keys.
 r3109@asus:  jeremy | 2005-11-16 00:09:08 -0800
 double-quote rather than single-quote sqlite columns
 r3110@asus:  jeremy | 2005-11-16 00:09:56 -0800
 quote column names and use attribute_condition in validates_uniqueness_of
 r3111@asus:  jeremy | 2005-11-16 00:12:24 -0800
 Use QUOTED_TYPE constant in tests
 r3112@asus:  jeremy | 2005-11-16 00:13:28 -0800
 restrict test_inserts_with_pre_and_suffix to those adapters which support migrations
 r3113@asus:  jeremy | 2005-11-16 00:14:09 -0800
 Use QUOTED_TYPE constant in tests
 r3114@asus:  jeremy | 2005-11-16 00:14:30 -0800
 Use QUOTED_TYPE constant in tests


git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3051 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

Added extension capabilities to has_many and has_and_belongs_to_many proxies [DHH] Added find_or_create_by_X as a second type of dynamic finder that'll create the record if it doesn't already exist [DHH] Added constrain scoping for creates using a hash of attributes bound to the :creation key [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2872 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

Added support for calling constrained class methods on has_many and has_and_belongs_to_many collections #1764 [Tobias Luetke]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1894 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

Fixed that single-table inheritance sub-classes couldn't be used to limit the result set with eager loading #1215 [Chris McGrath]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1619 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1131 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

Added new Base.find API and deprecated find_all, find_first. Added preliminary support for eager loading of associations

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1077 5ecf4fe2-1ee6-0310-87b1-e25e094e27de