What is the proper syntax to include and if statement while trying to write out a query? Basically, this value might be in the DB... if it is it needs to be in the query with a comma but if it's not it shouldn't be in the query with a comma.

The IN statement of the query is where my question is directed at:

PHP Code:

$sql2 = 'SELECT username'
. ' FROM sgforum_users'
. ' WHERE user_id'
. ' IN ( '.$row1['user_id_1'].''.if (isset($row1['user_id_2'])) echo (','.$row1['user_id_2']).''.if (isset($row1['user_id_3'])) echo (','.$row1['user_id_3']).''.if (isset($row1['user_id_4'])) echo (','.$row1['user_id_4']).' ) LIMIT 0, 30';

echo $sql2; 


$sql2 = 'SELECT username FROM sgforum_users WHERE user_id IN';

if (isset($row1['user_id_2']))
{
$sql2 .= $row1['user_id_2'];
} else {
// something else
}

// execute your query

I'd try the ternary operator.
E.g.,

PHP Code:

isset($row1['user_id_2']) ? ", $row1['user_id_2']" : "" 


http://us3.php.net/language.operators.comparison

In this case though, I'd just use a foreach to iterate through user_id_?, creating an array, then use implode to glue it together for the query.

id go with

PHP Code:

if (isset($row1['user_id_1'])) $inVars[]=$row1['user_id_1'];
if (isset($row1['user_id_2'])) $inVars[]=$row1['user_id_2'];
if (isset($row1['user_id_3'])) $inVars[]=$row1['user_id_3'];
if (isset($row1['user_id_4'])) $inVars[]=$row1['user_id_4'];
if (isset($row1['user_id_5'])) $inVars[]=$row1['user_id_5'];

$sql2 = 'SELECT username' 
. ' FROM sgforum_users' 
. ' WHERE user_id' 
. ' IN ( '.implode(',',$inVars).' ) LIMIT 0, 30';