Question

The following Oracle SQL code generates the error “ORA-02287: sequence number not allowed here“:

INSERT INTO Customer (CustomerID,Name) VALUES (Customer_Seq.nextval,'AAA');
SELECT * FROM Customer where CustomerID=Customer_Seq.currval;

The error occurs on the second line (SELECT statement). I don’t really understand the problem, because this does work:

INSERT INTO Customer (CustomerID,Name) VALUES (Customer_Seq.nextval,'AAA');
SELECT Customer_Seq.currval from dual;

Answer 1

You have posted some sample code, so it is not clear what you are trying to achieve. If you want to know the assigned value, say for passing to some other procedure you could do something like this:

SQL> var dno number
SQL> insert into dept (deptno, dname, loc)
  2      values (deptno_seq.nextval, 'IT', 'LONDON')
  3      returning deptno into :dno
  4  /

1 row created.

SQL> select * from dept
  2  where deptno = :dno
  3  /

    DEPTNO DNAME          LOC
---------- -------------- -------------
        55 IT             LONDON

SQL>

Edit

We can use the RETURNING clause to get the values of any column, including those which have been set with default values or by trigger code.