Help Needed In SQL Query

Question

HI All,
Oracle sql clarification required
Sample Table:
empno empname Job mgr_id hire_date salary deptno
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
7900 JAMES CLERK 7698 03-DEC-81 950 30
7369 SMITH CLERK 7902 17-DEC-80 800 20
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
Need "single / one" sql for this requirement statement:
There will be 2 drop down boxes (1st - Job list, 2nd - empno) in the form in which the following result set is expected
1) When user selects value from 1st drop down box (job) as "ANALYST" leaving the second drop down unselected, the result expected is 2 (no. of rows for that job)
2) When user selects value from 1st drop down box (job) as "ANALYST" and the value from 2nd drop down box as 7902, the result expected is 1 (no of rows for that job and empno)
Sqls which I have tried from my side (given below) didn't give the expected result and please do help me in correcting this
select count(1) from scott.emp where job='ANALYST' and ( empno = :empno or empno is null ) ;
Please help for this requirement. Any help is deeply appreciated.
Thanks
Zaheer

Answer 1

Hi,
welcome to the forum.
Please read SQL and PL/SQL FAQ
When you put some code or output please enclose it between two lines starting with {noformat}{noformat}
i.e.:
{noformat}{noformat}
SELECT ...
{noformat}{noformat}
For your question the following will both work:SQL> select * from emp
where job='ANALYST' and (empno =:empno or :empno is null)
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
7788 SCOTT ANALYST 7566 19/04/1987 00:00:00 3000 20
7902 FORD ANALYST 7566 03/12/1981 00:00:00 3000 20
2 rows selected.
SQL> select * from emp
where job='ANALYST' and empno =NVL(:empno, empno)
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
7788 SCOTT ANALYST 7566 19/04/1987 00:00:00 3000 20
7902 FORD ANALYST 7566 03/12/1981 00:00:00 3000 20
2 rows selected.
Regards.
Al