What could cause an ORA-00936 - Missing Expression with the following sql?

Question

We're seeing the error message ORA-00936 Missing Expression for the following SQL:

Note that this is just a cut-down version of a much bigger SQL so rewriting it to a inner join or similar is not really in the scope of this:

This is the SQL that fails:

select (select count(*) from gt_roster where ROS_ROSTERPLAN_ID = RPL_ID)
from gt_rosterplan
where RPL_ID = 432065061

What I've tried: * Extracting the innermost SQL and substituting the ID from the outer SQL gives me the number 12. * Aliasing both the sub-query, and the count(*) individually and both at the same time does not change the outcome (ie. still an error)

What else do I need to look at?

The above are only tables, no views, RPL_ID is primary key of gt_rosterplan, and ROS_ROSTERPLAN_ID is a foreign key to this column, there is basically no magic or hidden information here.

---

Edit: In response to answer, no, you do not need the aliases here as the columns are uniquely named across the tables.

---

Solved: The problem was that the client was running the wrong client driver version, 9.2.0.1, and there are known problems with that version.

Answer 1

That should work, assuming the column names are not ambiguous (and even if they were that would lead to a different error). I ran an equivalent statement and got a result without error:

SQL> select (select count(*) from emp2 where empdeptno = deptno)
  2  from dept
  3  where deptno=10
  4  /

(SELECTCOUNT(*)FROMEMP2WHEREEMPDEPTNO=DEPTNO)
---------------------------------------------
                                            3

Googling it appears that there are or have been Oracle bugs leading to ORA-00936 errors - see this for example.

Answer 2

The problem was that the client was running the wrong client driver version, 9.2.0.1, and there are known problems with that version.