select count(1) from (SELECT "TAB"."CODE", SUM("TAB"."SL"), FROM "TAB" WHERE "TAB"."UNIT" LIKE '21%' and "TAB"."ND" >= '2002' and "TAB"."ND" <= '2002' group by "TAB"."CODE") ;
SELECT count( distinct "TAB"."CODE") FROM "TAB" WHERE "TAB"."UNIT" LIKE '21%' and "TAB"."ND" >= '2002' and "TAB"."ND" <= '2002' ;
SUM("TAB"."SL"),
FROM "TAB"
WHERE "TAB"."UNIT" LIKE '21%' and "TAB"."ND" >= '2002' and "TAB"."ND" <= '2002'
group by "TAB"."CODE") ;
FROM "TAB"
WHERE "TAB"."UNIT" LIKE '21%' and "TAB"."ND" >= '2002' and "TAB"."ND" <= '2002' ;