CODEWITHSUNDEEP
sqlsql-server
user1152145
user1152145

Reputation: 295

SQL UPDATE statement with WHERE EXISTS

Im trying to write a query that updates a date only if the group im updating has a LINE_CD of 50. Would i do it like this?

UPDATE EMPLOYER_ADDL  
SET EMPLOYER_ADDL.GTL_UW_APPRV_DT = EMPLOYER_ADDL.DNTL_UW_APPRV_DT 
WHERE EXISTS
    ( 
      SELECT EMP_PLAN_LINE_INFO.LINE_CD
      FROM EMP_PLAN_LINE_INFO
      Where EMP_PLAN_LINE_INFO.GR_NBR = EMPLOYER_ADDL.GR_NBR and
       EMP_PLAN_LINE_INFO.LINE_CD = 50
     )

Upvotes: 17

Views: 123632

Answers (6)

Brain2000
Brain2000

Reputation: 4894

I believe exists requires a wildcard:

UPDATE EMPLOYER_ADDL  
SET EMPLOYER_ADDL.GTL_UW_APPRV_DT = EMPLOYER_ADDL.DNTL_UW_APPRV_DT 
WHERE EXISTS
    ( 
      SELECT *
      FROM EMP_PLAN_LINE_INFO
      Where EMP_PLAN_LINE_INFO.GR_NBR = EMPLOYER_ADDL.GR_NBR and
       EMP_PLAN_LINE_INFO.LINE_CD = 50
     )

I prefer using IN though. Some argue that it can be slower, but I have found the SQL optimizer in 2005 and higher make IN work the same as EXISTS if the field is a non-null field.

UPDATE EMPLOYER_ADDL  
SET EMPLOYER_ADDL.GTL_UW_APPRV_DT = EMPLOYER_ADDL.DNTL_UW_APPRV_DT 
WHERE EMPLOYER_ADDL.GR_NBR IN
    ( 
      SELECT EMP_PLAN_LINE_INFO.GR_NBR
      FROM EMP_PLAN_LINE_INFO
      Where EMP_PLAN_LINE_INFO.LINE_CD = 50
     )

Upvotes: 1

AJP
AJP

Reputation: 2125

I believe this will give you same result.

UPDATE ea
  SET GTL_UW_APPRV_DT = DNTL_UW_APPRV_DT
  FROM EMPLOYER_ADDL AS ea
  INNER JOIN EMP_PLAN_LINE_INFO AS ep
      ON ep.GR_NBR = ea.GR_NBR
      AND ep.LINE_CD = 50

Upvotes: 7

SQLMason
SQLMason

Reputation: 3275

Assuming that GR_NBR is a PK and distinct in EMP_Plan_line_Info:

UPDATE  EA
SET     GTL_UW_APPRV_DT = DNTL_UW_APPRV_DT
FROM    EMPLOYER_ADDL EA
        INNER JOIN EMP_PLAN_LINE_INFO EP
            ON EP.GR_NBR = EA.GR_NBR
               AND EP.LINE_CD = 50

Upvotes: 4

Pankaj
Pankaj

Reputation: 10095

Try with this also. I think this is new for you ?

UPDATE ADDL   
SET ADDL.GTL_UW_APPRV_DT = ADDL.DNTL_UW_APPRV_DT 
From EMPLOYER_ADDL ADDL
Inner Join  EMP_PLAN_LINE_INFO INFO on INFO.GR_NBR = ADDL.GR_NBR
Where INFO.LINE_CD = 50

Upvotes: 2

xbrady
xbrady

Reputation: 1703

What about this?

UPDATE ea  
SET ea.GTL_UW_APPRV_DT = ea.DNTL_UW_APPRV_DT 
FROM EMPLOYER_ADDL ea
    INNER JOIN EMP_PLAN_LINE_INFO ei ON(ei.GR_NBR = ea.GR_NBR)
WHERE 
ei.LINE_CD = 50

Upvotes: 13

anon
anon

Reputation: 

UPDATE ea
  SET GTL_UW_APPRV_DT = DNTL_UW_APPRV_DT
  FROM EMPLOYER_ADDL AS ea
  WHERE EXISTS
  (
    SELECT 1
      FROM EMP_PLAN_LINE_INFO AS ep
      WHERE ep.GR_NBR = ea.GR_NBR
      AND ep.LINE_CD = 50
  );

However, if you can derive this information from a query, why update the table? Seems like this will have to be run constantly else risk being out of date.

Upvotes: 23

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