UPdate IDM_DEV.COUNTRY_DIM set update_lineage_id
=(
SELECT
A.DM_LINEAGE_ID
FROM
CO c,
LINEAGE A
WHERE
A.PROCESS_NM = 'SP'
AND NOT EXISTS ( SELECT
A.DM_LINEAGE_ID
FROM
CON_DIM CON_DIM,
LINEAGE A
WHERE
C.COUNTRY_CD=CON_DIM.COUNTRY_CD AND
CON_DIM.COUNTRY_NM= C.COUNTRY_NM
AND A.PROCESS_NM ='SP'))

My requirement is I want to update the result of select query with an id...Since select gives mmore than 1 row,I get an error.

[IBM][CLI Driver][DB2/LINUXX8664] SQL0811N The result of a scalar fullselect, SELECT INTO statement, or VALUES INTO statement is more than one row. SQLSTATE=21000

Basically I want an update with select statement which returns multiple.

Please help

You can not have many values in a single cell...

Usually, one do that kind of update to denormalize a value, the syntax is:
UPDATE A SET Col1 = (

SELECT B.Col2 FROM B

WHERE B.Keys = A.Keys AND B.Col2 is not null AND B.OtherExpr)

WHERE EXISTS(

SELECT 1 FROM B

WHERE B.Keys = A.Keys AND B.Col2 is not null AND B.OtherExpr)

Can you write down what this is supposed to do ?

I have two tables: A and B

B is my target table.A is source table.I have to select rows in source table which got updated and the same rows in target which has to be updated.
I am doing that using select clause

SELECT
A.DM_LINEAGE_ID
FROM
CO c,
LINEAGE A
WHERE
A.PROCESS_NM = 'SP'
AND NOT EXISTS ( SELECT
A.DM_LINEAGE_ID
FROM
CON_DIM CON_DIM,
LINEAGE A
WHERE
C.COUNTRY_CD=CON_DIM.COUNTRY_CD AND
CON_DIM.COUNTRY_NM= C.COUNTRY_NM
AND A.PROCESS_NM ='SP'))
Now,I have an audit table which has an id value.I have to update the target table with the id value....

Your SQL looks bad because you do not have join criteria between your LINEAGE table and the others

Its beacuse source table has no relationship with Lineage ..

then it can not work...