無法更新Oracle中的暫存記錄，sql開發人員

Question

下面是我寫的更新給定字段的查詢，但其引發無法將char更新爲空錯誤。

UPDATE PS_H_BN_MCR_STG A SET A.H_BN_INITIAL_PARTN=(SELECT NVL(D.NAME_INITIALS,' ') 
    FROM PS_DEP_BEN_NAME D 
    WHERE D.EMPLID=A.EMPLID 
    AND D.DEPENDENT_BENEF=01 
    AND D.EFFDT=( 
SELECT MAX(D1.EFFDT) 
FROM PS_DEP_BEN_NAME D1 
WHERE D1.EMPLID=D.EMPLID 
    AND D1.DEPENDENT_BENEF=D.DEPENDENT_BENEF 
    AND D1.EFFDT<=SYSDATE)) WHERE A.MARITAL_STATUS IN (1,6,7); 

Answer 1

檢查您的解決方案成這樣子：（1）先更改列（H_BN_INITIAL_PARTN）現在下面query.then運行查詢允許空

alter table  PS_H_BN_MCR_STG 
 
modify (H_BN_INITIAL_PARTN NULL);

（2）