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author | Vijay Dev <vijaydev.cse@gmail.com> | 2011-06-20 02:12:21 +0530 |
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committer | Vijay Dev <vijaydev.cse@gmail.com> | 2011-06-20 02:12:21 +0530 |
commit | 5eac40bb7508947f181d8eb6bdff547ec3b4ef36 (patch) | |
tree | 49bbb618156e3e52f059f087d30810b0fcdf821d /railties/guides | |
parent | 9513474e5e41458e641fb38176b956c2b80b9a0a (diff) | |
download | rails-5eac40bb7508947f181d8eb6bdff547ec3b4ef36.tar.gz rails-5eac40bb7508947f181d8eb6bdff547ec3b4ef36.tar.bz2 rails-5eac40bb7508947f181d8eb6bdff547ec3b4ef36.zip |
document Active Record's reverse_order method
Diffstat (limited to 'railties/guides')
-rw-r--r-- | railties/guides/source/active_record_querying.textile | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/railties/guides/source/active_record_querying.textile b/railties/guides/source/active_record_querying.textile index b4ce60fcaa..e3871a3c34 100644 --- a/railties/guides/source/active_record_querying.textile +++ b/railties/guides/source/active_record_querying.textile @@ -57,6 +57,7 @@ The methods are: * +group+ * +order+ * +reorder+ +* +reverse_order+ * +limit+ * +offset+ * +joins+ @@ -550,6 +551,32 @@ In case the +reorder+ clause is not used, the SQL executed would be: SELECT * FROM posts WHERE id = 10 ORDER BY posted_at DESC </sql> +h4. +reverse_order+ + +The +reverse_order+ method reverses the ordering clause if specified. + +<ruby> +Client.where("orders_count > 10").order(:name).reverse_order +</ruby> + +The SQL that would be executed: +<sql> +SELECT * FROM clients WHERE orders_count > 10 ORDER BY name DESC +</sql> + +If no ordering clause is specified in the query, the +reverse_order+ orders by the primary key in reverse order. + +<ruby> +Client.where("orders_count > 10").reverse_order +</ruby> + +The SQL that would be executed: +<sql> +SELECT * FROM clients WHERE orders_count > 10 ORDER BY clients.id DESC +</sql> + +This method accepts *no* arguments. + h3. Readonly Objects Active Record provides +readonly+ method on a relation to explicitly disallow modification or deletion of any of the returned object. Any attempt to alter or destroy a readonly record will not succeed, raising an +ActiveRecord::ReadOnlyRecord+ exception. |