Oracle SQL UPDATE无法与NVL一起使用

Question

I have an Oracle sql table PS_Z_TREND_NOW_TBL and am trying to update the STATUS field for the 11 rows it contains. The subquery below should update 2 of the rows to a number. I want to set the other 9 rows to 0. But when I run the below sql I get this error: ORA-01407: cannot update ("SYSADM"."PS_Z_TREND_NOW_TBL"."STATUS") to NULL

UPDATE PS_Z_TREND_NOW_TBL a
SET STATUS = 
(
SELECT count(SEC.IS_AW_AUTH_NAME)
from PS_IS_AW_SECURITY sec, PS_Z_TREND_NOW_TBL trend
where sec.IS_AW_AUTH_NAME LIKE '%Manager%'
and sec.IS_AW_GRP_ID LIKE '%' || REPLACE(UPPER(trend.DESCR254), ' ', '%') || '%'
and a.DESCR254 LIKE '%' || REPLACE(UPPER(trend.DESCR254), ' ', '%') || '%'
GROUP BY trend.DESCR254
)

I think I need to use the NVL function, but when I added that and ran the below query it updated all the STATUS field for all 11 rows to 0. Does anyone know what I need to do to change my query?

UPDATE PS_Z_TREND_NOW_TBL a
SET STATUS = 
NVL((
SELECT count(SEC.IS_AW_AUTH_NAME)
from PS_IS_AW_SECURITY sec, PS_Z_TREND_NOW_TBL trend
where sec.IS_AW_AUTH_NAME LIKE '%Manager%'
and sec.IS_AW_GRP_ID LIKE '%' || REPLACE(UPPER(trend.DESCR254), ' ', '%') || '%'
and a.DESCR254 LIKE '%' || REPLACE(UPPER(trend.DESCR254), ' ', '%') || '%'
GROUP BY trend.DESCR254
), '0')

Answer 1

I think you need a correlated subquery, so remove trend from the inner query. This may do what you want:

UPDATE PS_Z_TREND_NOW_TBL a
    SET STATUS = (SELECT count(SEC.IS_AW_AUTH_NAME)
                  from PS_IS_AW_SECURITY sec
                  where sec.IS_AW_AUTH_NAME LIKE '%Manager%' and
                        sec.IS_AW_GRP_ID LIKE '%' || REPLACE(UPPER(a.DESCR254), ' ', '%') || '%' 
                )