Since I added a case loop in my proc sql, the grouping does not work anymore

[sfmeier]

PROC SQL;
/* Entwicklung */
   CREATE TABLE TEMP AS  
   SELECT case    when t1.KONTO_ID in (&Nostrokonten)  
                    then 0 /* Nostrokonten */
                else t2.MLR_ProduktgruppeID
                end as MLR_ProduktgruppeID  format=mlr_produktgruppe.,  
                sum(Bilanzsaldo) as Bilanzsaldo format=commax18.2,
            t1.Stichtag
      FROM S1_KONTO&stichtag t1  
          LEFT JOIN DB.MAPPING_GAB2MLR_PRODUKTGRUPPE t2
        ON t1.GAB = t2.GAB
      GROUP BY MLR_ProduktgruppeID,
               Stichtag;
quit;

[Jeremy_Browne · Accepted solution]

Either use an alias for the case statement that is not the same as the variable (t2.)MLR_ProduktgruppeID: i.e. ..AS MLR_ProduktgruppeID_2 and use the alias in the GROUP BY.  Ambiguity between VAR and alias may be the issue AND/OR if that doesn't fix, also put the CASE statement longhand in the GROUP BY (without the AS...)