Explain COALESCE example in the docs.

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 0b6a109432ee1ace576c9b3653f233239cde3468..2f307c2b121f6460cd7b275b84bf972711b641eb 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -10015,6 +10015,8 @@ SELECT ... WHERE CASE WHEN x <> 0 THEN y/x > 1.5 ELSE false END;
 <programlisting>
 SELECT COALESCE(description, short_description, '(none)') ...
 </programlisting>
+   This returns <varname>description</> if it is not null, or
+   <varname>short_description</> if it is not null, or <literal>(none)</>.
   </para>
 
    <para>