Error when use"select case when sum() group by"

Question

SELECT REGION_CODE
,REGION_DESC
,CASE WHEN SUM(UP_SMS_TIMES) BETWEEN T2.SMS_MIN AND T2.SMS_MAX THEN T2.SMS_LVL_CODE END
FROM PMID.TB_MID_PAR_EXT_USER_MON T1, PCDE.TB_CDE_SMS_LVL T2
WHERE DEAL_DATE='200811'
GROUP BY REGION_CODE, REGION_DESC
{color:#ff0000}error:ORA-00979: not a GROUP BY expression
{color}{color:#000000}How can i fix the error,Thanks{color}

Answer 1

-- CREATE TABLE TB_MID_PAR_EXT_USER_MO
create table TB_MID_PAR_EXT_USER_MON
DEAL_DATE CHAR(6),
REGION_CODE CHAR(2),
REGION_DESC VARCHAR2(20),
UP_SMS_TIMES NUMBER(14) default 0,
--INSERT SAMPLE DATA TO TB_MID_PAR_EXT_USER_MO
insert into TB_MID_PAR_EXT_USER_MON(DEAL_DATE,REGION_CODE,REGION_DESC,UP_SMS_TIMES)
VALUES('200812','BJ','BEIJING'11)
insert into TB_MID_PAR_EXT_USER_MON(DEAL_DATE,REGION_CODE,REGION_DESC,UP_SMS_TIMES)
VALUES('200812','SH','SHANGHAI',7)
insert into TB_MID_PAR_EXT_USER_MON(DEAL_DATE,REGION_CODE,REGION_DESC,UP_SMS_TIMES)
VALUES('200812','SH','SHANGHAI',9)
insert into TB_MID_PAR_EXT_USER_MON(DEAL_DATE,REGION_CODE,REGION_DESC,UP_SMS_TIMES)
VALUES('200812','BJ','BEIJING',10)
insert into TB_MID_PAR_EXT_USER_MON(DEAL_DATE,REGION_CODE,REGION_DESC,UP_SMS_TIMES)
VALUES('200812','BJ','BEIJING',5)
insert into TB_MID_PAR_EXT_USER_MON(DEAL_DATE,REGION_CODE,REGION_DESC,UP_SMS_TIMES)
VALUES('200812','BJ','BEIJING',19)
---- CREATE TABLE TB_CDE_SMS_LVL
create table TB_CDE_SMS_LVL
SMS_LVL_CODE INTEGER,
SMS_LVL_DESC VARCHAR2(20),
SMS_MIN NUMBER(14,2),
SMS_MAX NUMBER(14,2)
--INSERT SAMPLE DATA TO TB_CDE_SMS_LVL
INSERT INTO TB_CDE_SMS_LVL(SMS_LVL_CODE,SMS_LVL_DESC,SMS_MIN,SMS_MAX)
VALUES(1,'0 ITEM',-1.00,0.00)
INSERT INTO TB_CDE_SMS_LVL(SMS_LVL_CODE,SMS_LVL_DESC,SMS_MIN,SMS_MAX)
VALUES(2,'0-20 ITEM',0.00,20.00)
INSERT INTO TB_CDE_SMS_LVL(SMS_LVL_CODE,SMS_LVL_DESC,SMS_MIN,SMS_MAX)
VALUES(3,'20-40 ITEM',20.00,40.00)
INSERT INTO TB_CDE_SMS_LVL(SMS_LVL_CODE,SMS_LVL_DESC,SMS_MIN,SMS_MAX)
VALUES(4,'40- ITEM',40.00,9999999.00)
--NOW,LET'S EXEC THE FOLLOWING STATEMENT
SELECT REGION_CODE,REGION_DESC
,MAX(CASE WHEN SUM(UP_SMS_TIMES) BETWEEN T2.SMS_MIN AND T2.SMS_MAX THEN T2.SMS_LVL_CODE END) AS SMS_LVL
FROM PMID.TB_MID_PAR_EXT_USER_MON T1,PCDE.TB_CDE_SMS_LVL T2
WHERE DEAL_DATE='200811' AND UP_SMS_TIMES>0
GROUP BY REGION_CODE, REGION_DESC
--MY REQUIRED RESULT IS
REGION_CODE REGION_DESC SMS_LVL
SH SHANGHAI 2
BJ BEIJING 4
Thanks you!