Document DELETE/UPDATE command tag behavior when triggers are involved.

robertmhaas · robertmhaas · commit 61dd737c2966 · 2011-10-10T12:53:04.000-04:00
Marti Raudsepp
diff --git a/doc/src/sgml/ref/delete.sgml b/doc/src/sgml/ref/delete.sgml
@@ -206,10 +206,12 @@ DELETE FROM [ ONLY ] <replaceable class="PARAMETER">table</replaceable> [ [ AS ]
 DELETE <replaceable class="parameter">count</replaceable>
 </screen>
    The <replaceable class="parameter">count</replaceable> is the number
-   of rows deleted.  If <replaceable class="parameter">count</replaceable> is
-   0, no rows matched the <replaceable
-   class="parameter">condition</replaceable> (this is not considered
-   an error).
+   of rows deleted.  Note that the number may be less than the number of
+   rows that matched the <replaceable
+   class="parameter">condition</replaceable> when deletes were
+   suppressed by a <literal>BEFORE DELETE</> trigger.  If <replaceable
+   class="parameter">count</replaceable> is 0, no rows were deleted by
+   the query (this is not considered an error).
   </para>
 
   <para>
diff --git a/doc/src/sgml/ref/update.sgml b/doc/src/sgml/ref/update.sgml
@@ -226,10 +226,12 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> [ [ AS ] <rep
 UPDATE <replaceable class="parameter">count</replaceable>
 </screen>
    The <replaceable class="parameter">count</replaceable> is the number
-   of rows updated.  If <replaceable class="parameter">count</replaceable> is
-   0, no rows matched the <replaceable
-   class="parameter">condition</replaceable> (this is not considered
-   an error).
+   of rows updated, including matched rows whose values did not change.
+   Note that the number may be less than the number of rows that matched
+   the <replaceable class="parameter">condition</replaceable> when
+   updates were suppressed by a <literal>BEFORE UPDATE</> trigger.  If
+   <replaceable class="parameter">count</replaceable> is 0, no rows were
+   updated by the query (this is not considered an error).
   </para>
 
   <para>
