MySQL server has gone away<pre>Array
(
    [0] => Error Number: 2006
    [1] => MySQL server has gone away
    [2] => SELECT *, IF(T.photoName!="", T.photoName, (
					SELECT photoName
					FROM Photos AS PH
					JOIN FormatContent_Photos AS PB ON PH.photoID=PB.photoID
					WHERE PB.contentID=T.contentID
					ORDER BY sortID LIMIT 1
				)) AS photoName FROM LearningCenter AS T WHERE isActive=1 ORDER BY sortID
)
</pre>