This matches our behavior in other cases where useful enumerable methods
might have a different definition in `Relation`. Wanting to actually
enumerate over the records in this case is completely reasonable, and
wanting `.sum` is reasonable for the same reason it is on `Enumerable`
in the first place.

Fixes #20626

revert create and drop task descriptions

raise ActiveModel::MissingAttributeError when trying to access a relationship without the foreign key attribute

fixes regression reported on #20253

ActiveRecord::Base#[] was not used cause of 8b954200

db:reset should not prematurely load the environment, so, for instance,
if there is any initializer that touches th DB, it will not touch that
before droping it.

Also this makes the code simpler.

This changed was made back in 15fb4302
, not sure why. But I am pretty much sure we should do it like this, as
drop and setup should load its dependencies tasks if necessary.

This used to raise a `IrreversibleMigration` error (since #10437).
However since `remove_index :table, :column` is probably the most basic
use-case we should make it reversible again.

Conflicts:
	activerecord/CHANGELOG.md

My impression of the code sample is that the intent is to assign guy_1, guy_2, etc. The code as it stood would have assigned guy_1, guy_1, etc.

This simply replaces the 1 with the iterator variable i.

[ci skip]

The examples now take in consideration when Active Record finds inverse
associations automatically.

the test case for this commit is in cd3f5dba

If a getter has side effects on the DB, `changes_applied` will be called
twice. The second time will try and remove the changed attributes cache,
and will crash because it's already been unset. This also demonstrates
that we shouldn't assume that calling getters won't change the value of
`changed_attributes`, and we need to clear the cache if an attribute is
modified.

Fixes #20531.

Fixes #17511 and #17415

`serialize` makes the contract that if it is given a class name, it will
never return something other than an instance of that class. This means
that it must cast `nil` to the empty form of that object. As such, we
should then persist empty forms of that object as `nil`. While this is
techincally under the contract of

```
model.attribute = value
assert_equal model.attribute, model.tap(&:save).reload.attribute
```

which we can't actually test universally without property based testing,
it has come up more than once and is worth calling out specifically
since we aren't looking to change it.

[Sean Griffin & jmondo]

If the subtype provides custom schema dumping behavior, we need to defer
to it. We purposely choose not to handle any values other than an array
(which technically should only ever be `nil`, but I'd rather code
defensively here).

Fixes #20515.

change AR clear order in ActionDisplatch::Reloader hook

[Robin Dupret & Shunsuke Aida]

Time instance will be casted so we don't have to do `to_s(:db)`.

This introduces a deprecation cycle to change the behavior of the
default point type in the PostgreSQL adapter. The old behavior will
continue to be available for the immediate future as `:legacy_point`.

The current behavior of returning an `Array` causes several problems,
the most significant of which is that we cannot differentiate between an
array of points, and a point itself in the case of a column with the
`point[]` type.

The attributes API gives us a reasonable way to have a proper
deprecation cycle for this change, so let's take advantage of it. If we
like this change, we can also add proper support for the other geometric
types (line, lseg, box, path, polygon, and circle), all of which are
just aliases for string today.

Fixes #20441

It was not being applied to creates and updates attempted through the
non-bang save methods. This means that, for example, creation of
records for singular associations through the `create_*` methods was
not appropriately ignored in .suppress blocks.

Improve the guide about `has_many` `collection.clear` to indicate
the behavior for each dependent strategy according to
`collection.delete_all`.

Based on #17179, I changed the `collection.delete` docs to also
clarify the default strategy for each `hm` and `hm:t` associations.

Fixes #20170.

since NUMBER(8) is not enough to store the maximum number of bigint.
Oracle NUMBER(p,0) as handled as integer
because there is no dedicated integer sql data type exist in Oracle database.

Also NUMBER(p,s) precision can take up to 38. p means the number of digits, not the byte length.
bigint type needs 19 digits as follows.

	$ irb
	2.2.2 :001 > limit = 8
	 => 8
	2.2.2 :002 > maxvalue_of_bigint = 1 << ( limit * 8 - 1)
	 => 9223372036854775808
	2.2.2 :003 > puts maxvalue_of_bigint.to_s.length
	19
	 => nil
	2.2.2 :004 >

Our general contract in Active Record is that strings are assumed to be
SQL literals, and symbols are assumed to reference a column. If a from
clause is given, we shouldn't include the table name, but we should
still quote the value as if it were a column.

Upon fixing this, the tests were still failing on SQLite. This was
because the column name being returned by the query was `"\"join\""`
instead of `"join"`. This is actually a bug in SQLite that was fixed a
long time ago, but I was using the version of SQLite included by OS X
which has this bug. Since I'm guessing this will be a common case for
contributors, I also added an explicit check with a more helpful error
message.

Fixes #20360