ORA-01407: cannot update ("SYSADM"."PS_N_CERTMOD_TAO4"."DATE_CHAR") to NULL Failed SQL stmt: /*UPDATE - peoplesoft

Question

Error Message: ORA-01407: cannot update
("SYSADM"."PS_N_CERTMOD_TAO4"."DATE_CHAR") to NULL Failed SQL stmt: /*UPDATE
When i am generating the report it is saying NO Success in Peoplesoft.
Below is the code which for Update statement.
Please help me how to overcome from this problem.
Thanks in Advance.
UPDATE %Table(N_CERTMOD_TAO) TMP
SET TMP.DATE_CHAR = ( CASE WHEN EXISTS(
SELECT A.descr254
FROM PS_N_CERTMONYR_DTL A
WHERE A.INSTITUTION = TMP.INSTITUTION
AND A.ACAD_CAREER = TMP.ACAD_CAREER
AND A.STRM = TMP.COMPLETION_TERM
AND A.ACAD_PROG = TMP.ACAD_PROG
AND A.ACAD_PLAN = TMP.ACAD_PLAN ) THEN (
SELECT A.descr254
FROM PS_N_CERTMONYR_DTL A
WHERE A.INSTITUTION = TMP.INSTITUTION
AND A.ACAD_CAREER = TMP.ACAD_CAREER
AND A.STRM = TMP.COMPLETION_TERM
AND A.ACAD_PROG = TMP.ACAD_PROG
AND A.ACAD_PLAN = TMP.ACAD_PLAN ) ELSE (CASE WHEN EXISTS(
SELECT A.descr254
FROM PS_N_CERTMONYR_DTL A
WHERE A.INSTITUTION = TMP.INSTITUTION
AND A.ACAD_CAREER = TMP.ACAD_CAREER
AND A.STRM = TMP.COMPLETION_TERM
AND A.ACAD_PROG = TMP.ACAD_PROG
AND A.ACAD_PLAN = ' ') THEN (
SELECT A.descr254
FROM PS_N_CERTMONYR_DTL A
WHERE A.INSTITUTION = TMP.INSTITUTION
AND A.ACAD_CAREER = TMP.ACAD_CAREER
AND A.STRM = TMP.COMPLETION_TERM
AND A.ACAD_PROG = TMP.ACAD_PROG
AND A.ACAD_PLAN = ' ') ELSE ( CASE WHEN EXISTS (
SELECT B.A_EXAM_SEM_DT
FROM PS_A_XM_WRES_DTT_P B
WHERE B.INSTITUTION = TMP.INSTITUTION
AND B.ACAD_CAREER = TMP.ACAD_CAREER
AND B.STRM = TMP.COMPLETION_TERM
AND B.ACAD_PROG = TMP.ACAD_PROG
AND B.ACAD_PLAN = TMP.ACAD_PLAN) THEN (
SELECT TO_CHAR(B.A_EXAM_SEM_DT)
FROM PS_A_XM_WRES_DTT_P B
WHERE B.INSTITUTION = TMP.INSTITUTION
AND B.ACAD_CAREER = TMP.ACAD_CAREER
AND B.STRM = TMP.COMPLETION_TERM
AND B.ACAD_PROG = TMP.ACAD_PROG
AND B.ACAD_PLAN = TMP.ACAD_PLAN) ELSE (
SELECT TO_CHAR(C.A_EXAM_SEM_DT)
FROM PS_A_EXAM_WRES_DTT C
WHERE C.INSTITUTION = TMP.INSTITUTION
AND C.ACAD_CAREER = TMP.ACAD_CAREER
AND C.STRM = TMP.COMPLETION_TERM
AND C.ACAD_PROG = TMP.ACAD_PROG ) END ) END ) END)

Answer 1

First part of correction is proposed by Jared.
I think C.A_EXAM_SEM_DT could be null as well, so you should change TO_CHAR(C.A_EXAM_SEM_DT) to NVL(TO_CHAR(C.A_EXAM_SEM_DT), ' '
Consider of simplifying the statement, something like
UPDATE %Table(N_CERTMOD_TAO) TMP
SET TMP.DATE_CHAR =
(select nvl(A.descr254, --no value? -->
nvl(AA.descr254, -- no value? -->
nvl(TO_CHAR(B.A_EXAM_SEM_DT), -- no value? -->
nvl(TO_CHAR(C.A_EXAM_SEM_DT), -- no value? -->
' ')))) -- default value
from dual D
left outer join PS_N_CERTMONYR_DTL A
on (A.INSTITUTION = TMP.INSTITUTION AND
A.ACAD_CAREER = TMP.ACAD_CAREER AND
A.STRM = TMP.COMPLETION_TERM AND
A.ACAD_PROG = TMP.ACAD_PROG AND
A.ACAD_PLAN = TMP.ACAD_PLAN)
left outer join PS_N_CERTMONYR_DTL AA
on (AA.INSTITUTION = TMP.INSTITUTION AND
AA.ACAD_CAREER = TMP.ACAD_CAREER AND
AA.STRM = TMP.COMPLETION_TERM AND
AA.ACAD_PROG = TMP.ACAD_PROG AND AA.ACAD_PLAN = ' ')
left outer join PS_A_XM_WRES_DTT_P B
on (B.INSTITUTION = TMP.INSTITUTION AND
B.ACAD_CAREER = TMP.ACAD_CAREER AND
B.STRM = TMP.COMPLETION_TERM AND
B.ACAD_PROG = TMP.ACAD_PROG AND
B.ACAD_PLAN = TMP.ACAD_PLAN)
left outer join PS_A_EXAM_WRES_DTT C
on (C.INSTITUTION = TMP.INSTITUTION AND
C.ACAD_CAREER = TMP.ACAD_CAREER AND
C.STRM = TMP.COMPLETION_TERM AND
C.ACAD_PROG = TMP.ACAD_PROG));

Answer 2

You need a final case condition so that if its going to be null it returns a ' ' instead.
UPDATE %Table(N_CERTMOD_TAO) TMP
SET TMP.DATE_CHAR = ( CASE
WHEN EXISTS(
SELECT A.descr254
FROM PS_N_CERTMONYR_DTL A
WHERE A.INSTITUTION = TMP.INSTITUTION
AND A.ACAD_CAREER = TMP.ACAD_CAREER
AND A.STRM = TMP.COMPLETION_TERM
AND A.ACAD_PROG = TMP.ACAD_PROG
AND A.ACAD_PLAN = TMP.ACAD_PLAN )
THEN (
SELECT A.descr254
FROM PS_N_CERTMONYR_DTL A
WHERE A.INSTITUTION = TMP.INSTITUTION
AND A.ACAD_CAREER = TMP.ACAD_CAREER
AND A.STRM = TMP.COMPLETION_TERM
AND A.ACAD_PROG = TMP.ACAD_PROG
AND A.ACAD_PLAN = TMP.ACAD_PLAN )
ELSE ( CASE
WHEN EXISTS(
SELECT A.descr254
FROM PS_N_CERTMONYR_DTL A
WHERE A.INSTITUTION = TMP.INSTITUTION
AND A.ACAD_CAREER = TMP.ACAD_CAREER
AND A.STRM = TMP.COMPLETION_TERM
AND A.ACAD_PROG = TMP.ACAD_PROG
AND A.ACAD_PLAN = ' ')
THEN (
SELECT A.descr254
FROM PS_N_CERTMONYR_DTL A
WHERE A.INSTITUTION = TMP.INSTITUTION
AND A.ACAD_CAREER = TMP.ACAD_CAREER
AND A.STRM = TMP.COMPLETION_TERM
AND A.ACAD_PROG = TMP.ACAD_PROG
AND A.ACAD_PLAN = ' ')
ELSE ( CASE
WHEN EXISTS (
SELECT B.A_EXAM_SEM_DT
FROM PS_A_XM_WRES_DTT_P B
WHERE B.INSTITUTION = TMP.INSTITUTION
AND B.ACAD_CAREER = TMP.ACAD_CAREER
AND B.STRM = TMP.COMPLETION_TERM
AND B.ACAD_PROG = TMP.ACAD_PROG
AND B.ACAD_PLAN = TMP.ACAD_PLAN)
THEN (
SELECT TO_CHAR(B.A_EXAM_SEM_DT)
FROM PS_A_XM_WRES_DTT_P B
WHERE B.INSTITUTION = TMP.INSTITUTION
AND B.ACAD_CAREER = TMP.ACAD_CAREER
AND B.STRM = TMP.COMPLETION_TERM
AND B.ACAD_PROG = TMP.ACAD_PROG
AND B.ACAD_PLAN = TMP.ACAD_PLAN)
ELSE ( CASE
WHEN EXISTS(
SELECT TO_CHAR(C.A_EXAM_SEM_DT)
FROM PS_A_EXAM_WRES_DTT C
WHERE C.INSTITUTION = TMP.INSTITUTION
AND C.ACAD_CAREER = TMP.ACAD_CAREER
AND C.STRM = TMP.COMPLETION_TERM
AND C.ACAD_PROG = TMP.ACAD_PROG )
THEN (
SELECT TO_CHAR(C.A_EXAM_SEM_DT)
FROM PS_A_EXAM_WRES_DTT C
WHERE C.INSTITUTION = TMP.INSTITUTION
AND C.ACAD_CAREER = TMP.ACAD_CAREER
AND C.STRM = TMP.COMPLETION_TERM
AND C.ACAD_PROG = TMP.ACAD_PROG )
ELSE
' '
END )
END )
END )
END)