ANSI SQL

Question

I wanted to test some SQL to make sure it was SQL 92 compliant. My understanding is that the command I was using was compilant.
I set on the validator:
ALTER SESSION SET flagger=FULL;and issued the statement:
SELECT
COALESCE(
NULL, 34, 13, 0
from
dual;But I get the error:
ERROR at line 4:
ORA-00097: use of Oracle SQL feature not in SQL92 Full Level
ORA-06550: line 4, column 1:
PLS-01413: Use of NULL an expression
ORA-06550: line 3, column 1:
PLS-01416: Use of <id> (<value>...) hereSo I tried this:
SELECT
COALESCE(
'', 34, 13, 0
from
dual;But get:
ERROR at line 4:
ORA-00097: use of Oracle SQL feature not in SQL92 Full Level
ORA-06550: line 4, column 3:
PLS-01466: Null strings are not allowed
ORA-06550: line 3, column 1:
PLS-01416: Use of <id> (<value>...) hereAny ideas what I am doing wrong, please?
Thanks

Answer 1

Yep it does sound a little like a cop out.
SQL> alter session set flagger=full;
Session altered.
SQL> select coalesce(null,34,2) from dual;
select coalesce(null,34,2) from dual
ERROR at line 1:
ORA-00097: use of Oracle SQL feature not in SQL92 Full Level
ORA-06550: line 2, column 17:
PLS-01413: Use of NULL an expression
ORA-06550: line 2, column 8:
PLS-01416: Use of <id> (<value>...) here
SQL> select coalesce(cast(null as number),34,2) from dual;
select coalesce(cast(null as number),34,2) from dual
ERROR at line 1:
ORA-00097: use of Oracle SQL feature not in SQL92 Full Level
ORA-06550: line 2, column 22:
PLS-01413: Use of NULL an expression
ORA-06550: line 2, column 17:
PLS-01416: Use of <id> (<value>...) here
ORA-06550: line 2, column 8:
PLS-01416: Use of <id> (<value>...) here
SQL> select coalesce((select null from dual),34,2) from dual;
COALESCE((SELECTNULLFROMDUAL),34,2)
                                 34
SQL>The embedded (select null from dual) still doesn't impart a datatype on the null
SQL> select dump((select null from dual)) from dual;
DUMP((SELECTNULLFROMDUAL))
NULL
SQL>So it can't be to do with data types. If it was then, as already mentioned, the CAST should fix the issue, although you could argue that CAST in itself is not SQL92 compliant so that's why you can't use that.
Hmmm.....