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Diffstat (limited to 'guides/source/active_record_querying.md')
| -rw-r--r-- | guides/source/active_record_querying.md | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md index f8c64cbd0c..373a98bb85 100644 --- a/guides/source/active_record_querying.md +++ b/guides/source/active_record_querying.md @@ -1,4 +1,4 @@ -**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** Active Record Query Interface ============================= @@ -257,6 +257,12 @@ It is equivalent to writing: Client.where(first_name: 'Lifo').take ``` +The SQL equivalent of the above is: + +```sql +SELECT * FROM clients WHERE (clients.first_name = 'Lifo') LIMIT 1 +``` + The `find_by!` method behaves exactly like `find_by`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found. For example: ```ruby @@ -1128,7 +1134,7 @@ This would generate a query which contains a `LEFT OUTER JOIN` whereas the If there was no `where` condition, this would generate the normal set of two queries. NOTE: Using `where` like this will only work when you pass it a Hash. For -SQL-fragments you need use `references` to force joined tables: +SQL-fragments you need to use `references` to force joined tables: ```ruby Article.includes(:comments).where("comments.visible = true").references(:comments) @@ -1269,7 +1275,7 @@ User.active.where(state: 'finished') # SELECT "users".* FROM "users" WHERE "users"."state" = 'active' AND "users"."state" = 'finished' ``` -If we do want the `last where clause` to win then `Relation#merge` can +If we do want the last `where` clause to win then `Relation#merge` can be used. ```ruby |