QGIS/resources/function_help/CASE ELSE

<h3>CASE expression</h3>
A conditional expression that can be used to evaluate multiple expressions and
return a result.

<h4>Syntax</h4>
<pre>
     CASE
        WHEN <i>condition</i> THEN <i>result</i>
        [ ...n ]
        [ ELSE <i>result</i> ]
     END
</pre>
[ ] marks optional components

<h4>Arguments</h4>
<!-- List args for functions here-->
<i>  WHEN condition</i> - The condition expression to evaluate. <br>
<i>  THEN result</i> - If <i>condition</i> evaluates to True then <i>result</i> is evaluated and returned. <br>
<i>  ELSE result</i> - If none of the above conditions evaluated to True then <i>result</i> is evaluated and returned. <br>

<h4>Example</h4>
<!-- Show example of function.-->
<pre>
    CASE
        WHEN <i>"column" IS NULL</i> THEN <i>'None'</i>
        ELSE <i>"column"</i>
    END
</pre>