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| author | Ryuta Kamizono <kamipo@gmail.com> | 2018-10-10 05:31:20 +0900 |
|---|---|---|
| committer | Ryuta Kamizono <kamipo@gmail.com> | 2018-10-10 05:31:20 +0900 |
| commit | 92ccb7c75fd0d07479ea3b458b405b8e6667e05f (patch) | |
| tree | 5b68a28c358ebe0009e41c4544eba6729db363b9 /activerecord/lib/arel/visitors/mysql.rb | |
| parent | 3101a4136bd62787e252d2658eee23001036fa0f (diff) | |
| download | rails-92ccb7c75fd0d07479ea3b458b405b8e6667e05f.tar.gz rails-92ccb7c75fd0d07479ea3b458b405b8e6667e05f.tar.bz2 rails-92ccb7c75fd0d07479ea3b458b405b8e6667e05f.zip | |
Improve DELETE with JOIN handling to avoid subqueries if possible
Before:
```
Pet Destroy (0.8ms) DELETE FROM `pets` WHERE `pets`.`pet_id` IN (SELECT `pet_id` FROM (SELECT DISTINCT `pets`.`pet_id` FROM `pets` LEFT OUTER JOIN `toys` ON `toys`.`pet_id` = `pets`.`pet_id` WHERE `toys`.`name` = ?) AS __active_record_temp) [["name", "Bone"]]
```
After:
```
Pet Destroy (1.0ms) DELETE `pets` FROM `pets` LEFT OUTER JOIN `toys` ON `toys`.`pet_id` = `pets`.`pet_id` WHERE `toys`.`name` = ? [["name", "Bone"]]
```
Diffstat (limited to 'activerecord/lib/arel/visitors/mysql.rb')
| -rw-r--r-- | activerecord/lib/arel/visitors/mysql.rb | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/activerecord/lib/arel/visitors/mysql.rb b/activerecord/lib/arel/visitors/mysql.rb index 9d9294fecc..5d10088427 100644 --- a/activerecord/lib/arel/visitors/mysql.rb +++ b/activerecord/lib/arel/visitors/mysql.rb @@ -75,14 +75,7 @@ module Arel # :nodoc: all o end end - - def prepare_delete_statement(o) - if o.offset || has_join_sources?(o) - super - else - o - end - end + alias :prepare_delete_statement :prepare_update_statement # MySQL is too stupid to create a temporary table for use subquery, so we have # to give it some prompting in the form of a subsubquery. |