ORA-00920：無效的關係運算符3

Question

create or replace view test as 
select b.npm1,b.nama,b.IPS,a.ket as ket1,b.IPK,a.ket as ket2 
from KHS b left join keterangan a on a.nilai = IPS and 
left join keterangan a on a.nilai = IPK 

請幫助我，我的代碼有什麼錯誤！

Answer 1

首先，你的兩個連接之間有一個「and」（這可能是錯誤的來源）。其次，即使想要連接兩次同一個表，也需要以不同的方式對錶進行別名。由此產生的代碼應該看起來像這樣：

CREATE OR REPLACE view test AS 
SELECT 
    b.npm1, 
    b.nama, 
    b.IPS, 
    a1.ket AS ket1, 
    b.IPK, 
    a2.ket AS ket2 
FROM KHS b 
    LEFT JOIN keterangan a1 
     ON a1.nilai = b.IPS 
    LEFT JOIN keterangan a2 
     ON a2.nilai = b.IPK