====== ifNull ======
~~NOTOC~~
<WRAP right box>
    string ifNull(
           string $fieldToCheck,
           mixed $replacementValue
           )
</WRAP>
===== Description ====
The function ''ifNull()'' returns a database-specific string providing the means to replace a null value with a specified replacement. If the value in the database is not null, the value is not updated. The two parameters are:

  - The field in the table to check.
  - The value to replace the null value with if it is found

===== Usage =====
<code php>
/*
 * Assume mysql database connection
*/
$ifNullString = $db->ifNull('pants_field','chinos');

/*
 * ifnullString returns 'CASE WHEN pants_field is null 
                              THEN 'chinos' 
                              ELSE pants_field 
                              END ";
*/

$SQL = "UPDATE attire 
           SET pants_field = $ifNullString";

$db->Execute($SQL);
</code>