This was a common pattern:
```
query = author.posts.select(:title)
connection.select_one(query)
```
However `.select` returns a ActiveRecord::AssociationRelation, which has
the bind information, so we can use that to get the right sql query.
Also fix select_rows on postgress and sqlite3 that were not using the binds
[fixes#7538]
[fixes#12017]
[related #13731]
[related #12056]
Dangerous name conflicts includes instance or class method conflicts
with methods defined within `ActiveRecord::Base` but not its ancestors,
as well as conflicts with methods generated by other enums on the same
class.
Fixes#13389.
Similar to dangerous attribute methods, a scope name conflict is
dangerous if it conflicts with an existing class method defined within
`ActiveRecord::Base` but not its ancestors.
See also #13389.
*Godfrey Chan*, *Philippe Creux*
With this we can write `Model#select(:aliased)`, `Model#order(:aliased)`,
`Model#reoder(aliased: :desc)`, etc.
Supplementary work to 54122067acaad39b277a5363c6d11d6804c7bf6b.
Since Rails 4.0, we add an ORDER BY in the `first` method to ensure consistent
results among different database engines. But for singular associations this
behavior is not needed since we will have one record to return. As this
ORDER BY option can lead some performance issues we are removing it for singular
associations accessors.
Fixes#12623.
This fixes a bug where `select(:id)` combined with `joins()` raised:
```
ActiveRecord::StatementInvalid: SQLite3::SQLException: ambiguous column name: id:
SELECT id, authors.author_address_id
FROM "posts"
INNER JOIN "authors"
ON "authors"."id" = "posts"."author_id"
ORDER BY posts.id LIMIT 3
```
The `select_values` are still String and Symbols because other parts (mainly calculations.rb)
rely on that fact.
/cc @tenderlove
Before this patch find_in_batches raises this error only on second iteration. So you will know about the problem only when you get the batch size threshold.
This commit bring the famous ordinal Array instance methods defined
in ActiveSupport into ActiveRecord as fully-fledged finders.
These finders ensure a default ascending order of the table's primary
key, and utilize the OFFSET SQL verb to locate the user's desired
record. If an offset is defined in the query, calling #second adds
to the offset to get the actual desired record.
Fixes#13743.
This fixes a regression (#13744) that was caused by 67d8bb9.
In 67d8bb9, we introduced lazy rollback for records, such that the
record's internal states and attributes are not restored immediately
after a transaction rollback, but deferred until they are first
accessed.
This optimization is only performed when the model does not have any
transactional callbacks (e.g. `after_commit` and `after_create`).
Unfortunately, the models used to test the affected codepaths all
comes with some sort of transactional callbacks. Therefore this
codepath remains largely untested until now and as a result there are
a few issues in the implementation that remains hidden until now.
First, the `sync_with_transaction_state` (or more accurately,
`update_attributes_from_transaction_state`) would perform the
synchronization prematurely before a transaction is finalized (i.e.
comitted or rolled back). As a result, when the actuall rollback
happens, the record will incorrectly assumes that its internal states
match the transaction state, and neglect to perform the restore.
Second, `update_attributes_from_transaction_state` calls `committed!`
in some cases. This in turns checks for the `destroyed?` state which
also requires synchronization with the transaction stae, which causes
an infnite recurrsion.
This fix works by deferring the synchronization until the transaction
has been finalized (addressing the first point), and also unrolled
the `committed!` and `rolledback!` logic in-place (addressing the
second point).
It should be noted that the primary purpose of the `committed!` and
`rolledback!` methods are to trigger the relevant transactional
callbacks. Since this code path is only entered when there are no
transactional callbacks on the model, this shouldn't be necessary. By
unrolling the method calls, the intention here (to restore the states
when necessary) becomes more clear.
The `subclass_from_attrs` method is called even if the column specified by
the `inheritance_column` setting doesn't exist. This prevents setting associations
via the attributes hash if the association name clashes with the value of the setting,
typically `:type`. This worked previously in Rails 3.2.
Currently Active Record can be configured via the environment variable `DATABASE_URL` or by manually injecting a hash of values which is what Rails does, reading in `database.yml` and setting Active Record appropriately. Active Record expects to be able to use `DATABASE_URL` without the use of Rails, and we cannot rip out this functionality without deprecating. This presents a problem though when both config is set, and a `DATABASE_URL` is present. Currently the `DATABASE_URL` should "win" and none of the values in `database.yml` are used. This is somewhat unexpected to me if I were to set values such as `pool` in the `production:` group of `database.yml` they are ignored.
There are many ways that active record initiates a connection today:
- Stand Alone (without rails)
- `rake db:<tasks>`
- ActiveRecord.establish_connection
- With Rails
- `rake db:<tasks>`
- `rails <server> | <console>`
- `rails dbconsole`
We should make all of these behave exactly the same way. The best way to do this is to put all of this logic in one place so it is guaranteed to be used.
Here is my prosed matrix of how this behavior should work:
```
No database.yml
No DATABASE_URL
=> Error
```
```
database.yml present
No DATABASE_URL
=> Use database.yml configuration
```
```
No database.yml
DATABASE_URL present
=> use DATABASE_URL configuration
```
```
database.yml present
DATABASE_URL present
=> Merged into `url` sub key. If both specify `url` sub key, the `database.yml` `url`
sub key "wins". If other paramaters `adapter` or `database` are specified in YAML,
they are discarded as the `url` sub key "wins".
```
### Implementation
Current implementation uses `ActiveRecord::Base.configurations` to resolve and merge all connection information before returning. This is achieved through a utility class: `ActiveRecord::ConnectionHandling::MergeAndResolveDefaultUrlConfig`.
To understand the exact behavior of this class, it is best to review the behavior in activerecord/test/cases/connection_adapters/connection_handler_test.rb though it should match the above proposal.
- Earlier, change_table was creating database-agnostic object.
- After this change, it will create correct object based on current
database adapter.
- This will ensure that create_table and change_table will get same objects.
- This makes update_table_definition method public and nodoc.
- Fixes#13577 and #13503
Renaming the test accordingly to its behaviour
Adding 'Fixes' statement to changelog
Improving tests legibility & changelog
Undoing mistakenly removed empty line & further improving changelog
These methods were only used for the `IdentityMap` which was removed.
They are no longer used internally and should be removed without replacement.
As they were not `:nodoc:`'ed it's better to deprecate them before removal.
* Move check from generated helper to test_help.rb, so that all
applications can benefit
* Rather than just raising when the test schema has pending migrations,
try to load in the schema and only raise if there are pending
migrations afterwards
* Opt out of the check by setting
config.active_record.maintain_test_schema = false
* Deprecate db:test:* tasks. The test helper is now fully responsible
for maintaining the test schema, so we don't need rake tasks for this.
This is also a speed improvement since we're no longer reloading the
test database on every call to "rake test".
