SQL Query problem (Query not working as expected)

Question

Hi guys,
Today i built a query which is something like
Select from (Select * from (TableName) Where (Condition)) ALIAS where ALIAS.columnName = (some paramerter);*
I wrote this query thinking that first inner subquery will be executed and then the WHERE clause will be applied..
But the results returned by this query are not the same as expected.
I ran the inner sub-query as a separate query and saw that results should be properly returned if Outer WHERE clause is applied on those results(returned by sub-query).
But the results being returned after executing the complete query are different..
Please help me..How could it be possible??
If it is possible..then what is the alternative approach.??
Edited by: 854509 on 13 Sep, 2011 5:54 AM

Answer 1

SELECT *
FROM (SELECT *
FROM emp
WHERE sal > 800) detail
WHERE detail.job = 'SALESMAN'
OUTPUT :
EMPNO     ENAME     JOB     MGR     HIREDATE     SAL     COMM     DEPTNO
7499     ALLEN     SALESMAN     7698     02/20/81     1600     300     30
7521     WARD     SALESMAN     7698     02/22/81     1250     500     30
7654     MARTIN     SALESMAN     7698     09/28/81     1250     1400     30
7844     TURNER     SALESMAN     7698     09/08/81     1500          30
REGARDS,
FRIEND