Oracle merging column is giving error

Question

I have 2 columns in oracle, that I am merging like below

select SURVEY_AREA_7_12 || ' ' || HISSA_NO_7_12 
from XXCUS.XXACL_PN_FARMING_MST

which is working fine. But when I add my own name to the columns like below

select SURVEY_AREA_7_12 || ' ' || HISSA_NO_7_12 as 712_Column 
from XXCUS.XXACL_PN_FARMING_MST

it gives error as

ORA-00923: FROM keyword not found where expected

Answer 1

The problem is that your alias has a number in first position; you can quote it or change the alias:

Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - 64bit Production
SQL> select 'a' as 1ABC from dual;
select 'a' as 1ABC from dual
              *
ERROR at line 1:
ORA-00923: FROM keyword not found where expected


SQL> select 'a' as "1ABC" from dual;

1ABC
----
a

A number in a position different from the first gives no problem:

SQL> select 'a' as ABC1 from dual;

ABC1
----
a

Answer 2

712_Column is an invalid SQL identifier. You can't start an identifier with a number. If you need this, you need to quote the name:

select SURVEY_AREA_7_12 || ' ' || HISSA_NO_7_12 as "712_Column"
from XXCUS.XXACL_PN_FARMING_MST