Updating TABLEA based on values in TABLEB

Question

Hi: I have the two following tables. I want to write a query which updates fields in TABLE1 based on certain values in TABLE2
1. Update SEVERITY in TABLE1 with SVRT_CD in TABLE2 for all TABLE1.INCIDENT = TABLE2.TKT_NBR
2. Update ESCALATION in TABLE1 with ESCL_LVL in TABLE2 for all TABLE1.INCIDENT = TABLE2.TKT_NBR
3. If the TABLE2.MNS_STATUS is 5 then set TABLE1.INCIDENTSTATUS='Acls' for all TABLE1.INCIDENT = TABLE2.TKT_NBR
4. If the TABLE2.MNS_STATUS is 4 then set TABLE1.INCIDENTSTATUS='Bctk' for all TABLE1.INCIDENT = TABLE2.TKT_NBR
remedy@MDS> descr TABLE1;
USERID         NOT NULL VARCHAR2(32)
INCIDENT       NOT NULL VARCHAR2(64)
INCIDENTSTATUS NULL     VARCHAR2(16)
SEVERITY       NULL     NUMBER
ESCALATION     NULL     NUMBER
ONSTRAINT user_pk PRIMARY KEY (USERID,INCIDENT)
netcool@RMDSP02> describe TABLE2;
TKT_NBR                     NULL     NUMBER(10,0)
ESCL_LVL                    NULL     NUMBER(2,0)
SVRT_CD                     NULL     VARCHAR2(1)
MNS_STATUS                  NULL     NUMBER(1,0)
CONSTRAINT tkt_pk PRIMARY KEY (TKT_NBR)I think this will do what I want in #1 and #2. Can someone confirm?
UPDATE TABLE1
SET (SEVERITY, ESCALATION) = (SELECT SVRT_CD,ESCL_LVL from TABLE2 where to_number(TABLE1.INCIDENT) = TABLE2.TKT_NBR)Not sure how do I do the #3 and #4.
Thanks
Ravi

Answer 1

For point 3 and 4 use decode. and dont forget to use EXISTS in your update.
UPDATE table1
   SET (severity,
        escalation,
        incidentstatus) = (SELECT svrt_cd,
                            escl_lvl,
                            DECODE(mns_status,5,'Acls',4,'Bctk')
                       FROM table2
                      WHERE TO_NUMBER(table1.incident) = TABLE2.TKT_NBR)
WHERE EXISTS (SELECT NULL
              FROM table2
             WHERE TO_NUMBER(table1.incident) = TABLE2.TKT_NBR)        Thanks,
Karthick.