Most types of content require additional attributes. For a photo, we probably also want to store the pixel width and height at the very least:
- create table images (
+
+ create table images (
image_id integer
constraint images_image_id_fk
references cr_revisions
constraint images_pk
primary key,
width integer,
height integer
- );
+ );
+
Content types are nothing more than standard ACS Objects that inherit from content_revision:
-begin
+
+begin
acs_object_type.create_type (
supertype => 'content_revision',
@@ -59,7 +62,8 @@
end;
/
-show errors
+show errors
+
Note that content types always extend content_revision, rather than content_item. This is because we want to store multiple revisions of both the @@ -75,7 +79,8 @@
In the simple case where each user is allowed a single portrait, we can simply define a relationship between user and image as ACS Objects:
- acs_rel_type.create_role('user');
+
+ acs_rel_type.create_role('user');
acs_rel_type.create_role('portrait');
acs_rel_type.create_type( rel_type => 'user_portrait_rel',
@@ -88,7 +93,8 @@
object_type_two => 'content_item',
min_n_rels_two => 0,
max_n_rels_two => 1
- );
+ );
+
Note that the user object is related to a content_item object rather than an image object directly. Each image object represents only a @@ -98,16 +104,20 @@
Now we have defined both a content type and relationship type, we can start storing portraits. The DML for processing a new portrait upload form would look like this:
- begin transaction
+
+ begin transaction
:item_id := content_item.new(:name, :item_id, sysdate, NULL, '[ns_conn peeraddr]');
# maybe have content_revision return the LOB locator so that it can
# be used directly with blob_dml_file
:revision_id := content_revision.new(:title, :description, $publish_date, :mime_type, NULL, :text, 'content_revision',
:item_id, :revision_id);
blob_dml_file update cr_revisions set content = empty_blob() ...
- :rel_id := acs_rel.new(...)
+ :rel_id := acs_rel.new(...)
+
ns_ora write_blob ...+
+ ns_ora write_blob ... +
Last Modified: $Id: storage.html,v 1.2.2.1 2021/04/05 19:49:49