* Clarify what the situation is and what to do.
* Advise loading schema using `rake db:setup` instead of migrating.
* Use a rescue in the initializer rather than extending the error
  message in-place.
* Preserve the original backtrace of other errors by using `raise`
  rather than raising again with `raise error`.

References 0ec45cd1

This is a follow-up fix to f7a6b115 and
06082f66

This patch registers custom domains in our OID-type_map.
They will behave exactly as the type specified by `pg_type.typbasetype`.

/cc @matthewd

PostgreSQL determine `Column#type` through corresponding OID. #7814

I ran the whole test suite and compared the old to the new types.
Following is the list of types that did change with this patch:

```
DIFFERENT TYPE FOR mood: NEW: enum, BEFORE:
DIFFERENT TYPE FOR floatrange: NEW: floatrange, BEFORE: float
```

The `floatrange` is a custom type. The old type `float` was simply a coincidence
form the name `floatrange` and our type-guessing.

refactor assert_sql query to reuse capture_sql

set assert_sql to reuse the capture_sql method from above
instead of repeating the code

in response to comments on issue #14546

Fix delete all to not produce sql in statement

When delete_all is run on a CollectionProxy and has a
dependency of delete_all the SQL that is produced has an IN
statement. (DELETE FROM `associated_model` where `associated_model`
.`parent_id` = 1 AND `associated_model`.`id` IN (1, 2, 3...)).
This only happens if the association is not loaded (both loaded
and non-loaded delete_all should behave the same. This is a huge
problem when it comes to deleting many records because the query
becomes very slow. Instead the SQL produced should be (DELETE FROM
`assoicated_model` where `associated_model`.`parent_model_id`=1).

I fixed this by making sure the check for loaded and destroy also
makes sure that the dependent is not delete_all, so the conditional
goes to the else and deletes the records directly without the IN
statement.

delete_all sql if an association is not loaded should behave
the same as if the association is loaded. This test ensures
the SQL statements are exactly the same.

Other methods compare specific patterns, this method outputs
the actual sql query that is generated.

Do not overwrite selected and disabled attributes

Fix release task

Add a parentheses.
related: b4c96490

Fix polymorphic preloads on NOT NULL _type columns

We have `connection_adapters/column.rb` so it's easier to remember
that the column in in a separate file.

Tiny doc fix for Strong Parameters

- accepts_nested_attribute_for -> accepts_nested_attributes_for

The new method relies on AR::Associations::Association knowing about both reflection and a model class.

AR::Base#association now raises a descriptive error when trying to access non-existent associations. Previously it would blow up with a confusing NoMethodError: undefined method `association_class' for nil:NilClass.

remove calls to sql_type on pg columns

Defer to Association#klass instead of having a custom/duplicate code.

Require yaml explicitly on #database_configuration

fixes #10613

It is already called inside type_to_sql method.

Refactor test to use DdlHelper.

Follow-Up to https://github.com/rails/rails/pull/14400

This ensures that all tables are removed after each test and thereby
allowing us to run the tests in a random order.

append link to bad code when error type is SyntaxError

Fix tests not unsubscribing from Notifications.

Ensure we are returning either `true` or `false` for `#==`

460eb83d cused `ActiveRecord::Base#==` to sometimes return `nil` in some cases,
this ensures we always return a boolean value. Also fixed a similar problem in
AR reflections.

See https://github.com/rails/rails/blob/master/activesupport/lib/active_support/notifications.rb#L131

Replace trivial regexp with string or include, twice as fast