Order by in UNION

[chukkala]

Hi all

How can I specify order by clause for the follwing query If I give the following query its giving the following error

ERROR at line 3:
ORA-00904: invalid column name

If I remove 'order by a.Case_typ' its returning the rows.

SELECT DISTINCT A.CASE_TYP||A.CASE_SNO||'/'||CASE_YR,A.PTY_TYP||'->'||A.ACU_RID||'.'||A.ACU_NAME||','||A.CASE_TYP||A.CASE_SNO||'/'||A.CASE_YR FROM VEFS_CRMACU A WHERE A.CASE_TYP = 'CC'
union
SELECT DISTINCT A.CASE_TYP,A.PTY_TYP||'->'||A.DPP_RID||'.'||A.DPP_NAME||','||A.CASE_TYP||A.CASE_SNO||'/'||A.CASE_YR FROM VEFS_CRMDPP A WHERE A.CASE_TYP = 'CC' order by a.Case_typ

Thanks for your help

[SANJAY_G]

Use the column position in order by clause.
e.g. ORDER BY 1, 2, 3

[chukkala]

Thanks Sanjay

Its working now.