where (spalte1 = 0 and spalte2 <> 0) or (spalte3 <> 0) 

where ( $spalte1 != 0 || ($spalte2 != 0 && $spalte3 == 0) ) 

SELECT * FROM tabelle WHERE spalte1!=0 OR (spalte2!=0 AND spalte3=0) 

WHERE (spalte1 <> 0 and Spalte2 = 0 and Spalte3 = 0) or (Spalte2 = 0 and Spalte3 <> 0)