How do you send NULL as a variable from PHP to SQL?

Question

I want to send a value of \"NULL\" to a column in mySQL.

   $ParentEventID = \"NULL\";

   mysql_query(\"UPDATE events SET 
     ParentEventID = \'$ParentEventID         


        

Answer 1

You are on the right track making "NULL" a string. If you need to set it NULL, then remove the qoutes around $ParentEventID.

mysql_query("UPDATE events SET ParentEventID = $ParentEventID");

However, before doing so make sure that the value of $ParentEventID === NULL.