Substring Error? - forum topic by sophiachan

WHERE ...
AND SUBSTRING(CASE WHEN TABLE_A.COL_1 IS NOT NULL THEN TABLE_A.COL_1 ELSE TABLE_B.COL_1 END, LENGTH(CASE WHEN TABLE_A.COL_1 IS NOT NULL THEN TABLE_A.COL_1 ELSE TABLE_B.COL_1 END)-11,12) IN (SELECT COL_1 FROM TABLE_C)
 It says expect something between 'END' and ',' but what will it be?  I tried to add () to the case statement but still doesn't work...  Anyone?  Thanks!