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rails--rails/activerecord/lib/arel/delete_manager.rb
Ryuta Kamizono 859fba7c4b Handle DELETE with LIMIT in Arel
MySQL supports DELETE with LIMIT and ORDER BY.

https://dev.mysql.com/doc/refman/8.0/en/delete.html

Before:

```
  Post Destroy (1.0ms)  DELETE FROM `posts` WHERE `posts`.`id` IN (SELECT `id` FROM (SELECT `posts`.`id` FROM `posts` WHERE `posts`.`author_id` = ? ORDER BY `posts`.`id` ASC LIMIT ?) __active_record_temp)  [["author_id", 1], ["LIMIT", 1]]
```

After:

```
  Post Destroy (0.4ms)  DELETE FROM `posts` WHERE `posts`.`author_id` = ? ORDER BY `posts`.`id` ASC LIMIT ?  [["author_id", 1], ["LIMIT", 1]]
```
2018-09-30 21:21:54 +09:00

18 lines
323 B
Ruby

# frozen_string_literal: true
module Arel # :nodoc: all
class DeleteManager < Arel::TreeManager
include TreeManager::StatementMethods
def initialize
super
@ast = Nodes::DeleteStatement.new
@ctx = @ast
end
def from(relation)
@ast.relation = relation
self
end
end
end