===== Database Table Description of "album_content" =====

=== Name ===

album_content

=== Description ===

This table keeps track of what photos are in which albums. 

=== Purpose ===

Unlike folders, it's possible for a photo to be in more than one album.  This table allows for that.

=== Schema ===

<code sql>
create table album_content (
  identifier            integer not null primary key,
  photo                 integer not null references photo(identifier),
  album                 integer not null references album(identifier),
  version               integer not null references photo_version(identifier),
  date_changed          timestamp without time zone
);
</code>

=== References tables ===

  * album references [[album sql table|album]](identifier)
  * photo references [[photo sql table|photo]](identifier)
  * version references [[photo_version sql table|photo_version]](identifier)

=== Is referenced by tables ===

None. 

=== Related sequences ===

  * [[album_content_id_sequence sql sequence|album_content_id_sequence]]

=== Related indexes ===

  * [[album_content_album_idx sql index|album_content_album_idx]]
  * <del>[[album_content_id_idx sql index|album_content_id_idx]]</del> removed in 2.34
  * [[album_content_photo_idx sql index|album_content_photo_idx]]
  * [[album_content_version_idx sql index|album_content_version_idx]]

=== Related functions ===

  * [[count_photos_by_album sql function|count_photos_by_album]]
  * [[count_photos_by_user sql function|count_photos_by_user]]

=== Related views ===

None.

=== History ===

== Used first ==

Version 2.5

== Used last ==

Still in use

== Schema change history ==

= Version 2.5 =

<code sql>
create table album_content (
  identifier            integer not null primary key,
  photo                 integer not null references photo(identifier),
  album                 integer not null references album(identifier)
);
</code>

= Version 2.34 =

<code sql>
-- Add 'version' to album_content to allow individual versions.
ALTER TABLE album_content
  ADD version integer REFERENCES photo_version(identifier);
</code>

<code sql>
ALTER TABLE album_content ALTER version SET NOT NULL;
</code>

<code>
alter table album_content add date_added timestamp without time zone;
</code>

== Data change history =

= Version 2.34 =

<code sql>
UPDATE album_content set version =
   (SELECT identifier from photo_version v
    WHERE album_content.photo = v.photo AND v.master = 't');
</code>