Add more limited large object trigger example.

This commit is contained in:
Bruce Momjian 2012-08-14 23:25:20 -04:00
parent 9e84cccff2
commit 864de654c8

View file

@ -77,13 +77,8 @@ CREATE TRIGGER t_raster BEFORE UPDATE OR DELETE ON image
For each column that will contain unique references to large objects,
create a <literal>BEFORE UPDATE OR DELETE</> trigger, and give the column
name as the sole trigger argument. You can also restrict the trigger
to only execute on updates to the column with:
<programlisting>
CREATE TRIGGER t_raster BEFORE UPDATE OF raster OR DELETE ON image
FOR EACH ROW EXECUTE PROCEDURE lo_manage(raster);
</programlisting>
to only execute on updates to the column by using <literal>BEFORE UPDATE
OF</literal> <replaceable class="parameter">column_name</replaceable>.
If you need multiple <type>lo</>
columns in the same table, create a separate trigger for each one,
remembering to give a different name to each trigger on the same table.