DB2上一个季月SQL   CREATE FUNCTION "DB2INST1"."QTR"   www.2cto.com    ("DDATE" DATE  )    RETURNS CHARACTER(7)   SPECIFIC "DB2INST1"."SQL130225092927300"   LANGUAGE SQL   NOT DETERMINISTIC   READS SQL DATA   STATIC DISPATCH   CALLED ON NULL INPUT   EXTERNAL ACTION   INHERIT SPECIAL REGISTERS   BEGIN ATOMIC     DECLARE v CHARACTER(7) default '';     --declare cursor1 cursor for     set v= (       select           CASE             WHEN TO_CHAR(DDATE,'Q') ='1'               THEN to_char(year(DDATE)-1)||'-12'             when TO_CHAR(DDATE,'Q') ='2'               THEN to_char(year(DDATE))||'-03'             when TO_CHAR(DDATE,'Q') ='3'               THEN to_char(year(DDATE))||'-06'             when TO_CHAR(DDATE,'Q') ='4'               THEN to_char(year(DDATE))||'-09'           END         --into :v     -- 上个季月 能够知道跨年         from sysibm.sysdummy1         fetch first 1 rows only ) ;     --fetch first 1 rows only     --set sum = a + b;     return v;   END;