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Diffstat (limited to 'guides/source/active_record_querying.md')
| -rw-r--r-- | guides/source/active_record_querying.md | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md index 644756906a..31220f9be2 100644 --- a/guides/source/active_record_querying.md +++ b/guides/source/active_record_querying.md @@ -50,7 +50,7 @@ class Role < ApplicationRecord end ``` -Active Record will perform queries on the database for you and is compatible with most database systems, including MySQL, MariaDB, PostgreSQL and SQLite. Regardless of which database system you're using, the Active Record method format will always be the same. +Active Record will perform queries on the database for you and is compatible with most database systems, including MySQL, MariaDB, PostgreSQL, and SQLite. Regardless of which database system you're using, the Active Record method format will always be the same. Retrieving Objects from the Database ------------------------------------ @@ -81,7 +81,6 @@ The methods are: * `reorder` * `reverse_order` * `select` -* `distinct` * `where` Finder methods that return a collection, such as `where` and `group`, return an instance of `ActiveRecord::Relation`. Methods that find a single entity, such as `find` and `first`, return a single instance of the model. @@ -954,6 +953,9 @@ class Client < ApplicationRecord end ``` +NOTE: Please note that the optimistic locking will be ignored if you update the +locking column's value. + ### Pessimistic Locking Pessimistic locking uses a locking mechanism provided by the underlying database. Using `lock` when building a relation obtains an exclusive lock on the selected rows. Relations using `lock` are usually wrapped inside a transaction for preventing deadlock conditions. |