Question

I am trying to write an SQL query. If it works in Oracle SQL Developer, I will use it in TableAdapters query. This is the query; DURUM doesn’t belong to any table but I will ad it as a field in the TableAdapter

Error is; ORA-00904: “DURUM”: invalid identifier

SELECT IPYYB_BELGE.BELGEID,
       IPYYB_MUELLIF.MUELLIFID,
       IPYYB_MUELLIF.AD,
       IPYYB_MUELLIF.SOYAD,
       IPYYB_MUELLIF.TCKIMLIKNO,
       IPYYB_BELGE.SERINO,
       IPYYB_PRM_BELGEGRUP.ACIKLAMA,
       IPYYB_BELGE.ALINMATARIHI,
       IPYYB_BELGE.SONGUNCELLEMETARIHI,
       IPYYB_PRM_MUELLIFUNVAN.ACIKLAMA AS UNVANACIKLAMA,
       DURUM,
       CASE
         WHEN IPYYB_BELGE.ALINMATARIHI >= 2012 THEN 'EDA'
         WHEN IPYYB_BELGE.ALINMATARIHI < 2012 THEN 'GECE'
       END AS DURUM
FROM IPYYB_MUELLIF,
     IPYYB_BELGE,
     IPYYB_PRM_BELGEGRUP,
     IPYYB_PRM_MUELLIFUNVAN
WHERE IPYYB_MUELLIF.MUELLIFID = IPYYB_BELGE.MUELLIFID
AND   IPYYB_BELGE.GRUPID = IPYYB_PRM_BELGEGRUP.KOD
AND   IPYYB_MUELLIF.UNVAN = IPYYB_PRM_MUELLIFUNVAN.KOD (+)

The solution is

SELECT IPYYB_BELGE.BELGEID,
   IPYYB_MUELLIF.MUELLIFID,
   IPYYB_MUELLIF.AD,
   IPYYB_MUELLIF.SOYAD,
   IPYYB_MUELLIF.TCKIMLIKNO,
   IPYYB_BELGE.SERINO,
   IPYYB_PRM_BELGEGRUP.ACIKLAMA,
   IPYYB_BELGE.ALINMATARIHI,
   IPYYB_BELGE.SONGUNCELLEMETARIHI,
   IPYYB_PRM_MUELLIFUNVAN.ACIKLAMA AS UNVANACIKLAMA,

   (CASE
     WHEN IPYYB_BELGE.ALINMATARIHI >= 2012 THEN 'EDA'
     WHEN IPYYB_BELGE.ALINMATARIHI < 2012 THEN 'GECE'
   END) DURUM
FROM IPYYB_MUELLIF,
     IPYYB_BELGE,
     IPYYB_PRM_BELGEGRUP,
     IPYYB_PRM_MUELLIFUNVAN
WHERE IPYYB_MUELLIF.MUELLIFID = IPYYB_BELGE.MUELLIFID
AND   IPYYB_BELGE.GRUPID = IPYYB_PRM_BELGEGRUP.KOD
AND   IPYYB_MUELLIF.UNVAN = IPYYB_PRM_MUELLIFUNVAN.KOD (+)

Answer 1

Assuming "EDA" should be a character constant, you need to use single quotes, not double quotes.

"EDA" is a column name, whereas 'EDA' is a character literal

Edit

DURUM apears before your case statement. You cannot reference a column alias like that

Actually I think it’s not needed because the CASE statement will return a column named DURUM.