Question

I have a sequence named WCOMP_SEQ in oracle to generate auto increment column ON WCOMP table. When I insert a row to WCOMP table in SQLPlus, the row inserted and I can get the auto increment value using

SELECT WCOMP_SEQ.currval FROM dual

But when I ran insert a row using Database Class in CodeIgniter, the row inserted but when I ran the query above to get auto increment value I got Exception:

Exception: Undefined Index currval in E:...

How to fix this?

Answer 1

There is a way to get the value automatically assigned to a column: it is the RETURNING clause.

So, here is my sequence:

SQL> select emp_seq.currval from dual
  2  /

   CURRVAL
----------
      8140

SQL>

I’m going to use it in an INSERT statement:

SQL> var seqval number
SQL> insert into emp
  2  (empno, ename, deptno, sal, job)
  3  values
  4      (emp_seq.nextval, 'JELLEMA', 50, 4575, 'PAINTER')
  5  returning empno into :seqval
  6  /

1 row created.

SQL>

I returned the EMPNO into a SQL*Plus variable which I can print, and it has the same value as CURRVAL:

SQL> print :seqval

    SEQVAL
----------
      8141

SQL> select emp_seq.currval from dual
  2  /

   CURRVAL
----------
      8141

SQL>

Your next question is, “does CodeIgniter support the RETURNING sysntax?” I have no idea, but I suspect it does not. Most non-Oracle frameworks don’t.

There is always the option to wrap the INSERT statement in a stored procedure, but that’s an architectural decision whoch many people dislike.