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Diffstat (limited to 'guides')
| -rw-r--r-- | guides/source/active_record_querying.md | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md index 30493038e7..24dea0ec46 100644 --- a/guides/source/active_record_querying.md +++ b/guides/source/active_record_querying.md @@ -611,7 +611,8 @@ If you want to call `order` multiple times, subsequent orders will be appended t Client.order("orders_count ASC").order("created_at DESC") # SELECT * FROM clients ORDER BY orders_count ASC, created_at DESC ``` -WARNING: If you are using **MySQL 5.7.5** and above, then on selecting fields from a result set using methods like `select`, `pluck` and `ids`; the `order` method will raise an `ActiveRecord::StatementInvalid` exception unless the field(s) used in `order` clause are included in the select list. See the next section for selecting fields from the result set. + +WARNING: In most database systems, on selecting fields with `distinct` from a result set using methods like `select`, `pluck` and `ids`; the `order` method will raise an `ActiveRecord::StatementInvalid` exception unless the field(s) used in `order` clause are included in the select list. See the next section for selecting fields from the result set. Selecting Specific Fields ------------------------- @@ -818,19 +819,19 @@ Post.select(:title, :body).reselect(:created_at) The SQL that would be executed: ```sql -SELECT `posts.created_at` FROM `posts` +SELECT `posts`.`created_at` FROM `posts` ``` In case the `reselect` clause is not used, ```ruby -Post.select(:title, :body) +Post.select(:title, :body).select(:created_at) ``` the SQL executed would be: ```sql -SELECT `posts.title`, `posts.body` FROM `posts` +SELECT `posts`.`title`, `posts`.`body`, `posts`.`created_at` FROM `posts` ``` ### `reorder` |