Block with a SQL

Question

Hi Gurus,
I ahve a table named x. In that I have a column called feed_id. I need to construct a block which has the resultset as the below query.
select * from x where feed_id=(select max(feed_id) from x where pk=x.pk group by pk);
Can I use the Data block Wizard to accomplish this?
Is there any other way to do this?
Thanks,

Answer 1

Yes, you can use a From Clause Query. The easiest way is to use the data block wizard to build a block on the x table and then change the source and the advanced DML properties later.
Your query might not be as efficient as it could be. The following query is similar to yours, it gets all the employees whose deptno is the highest in the table, but it only selects from the table once. Rearranging your query along these lines might improve performance.
SELECT empno, ename, job, mgr, hiredate, sal, comm, deptno
FROM(
  SELECT e.*, Dense_Rank() over(ORDER BY deptno DESC) dr
  FROM emp e
WHERE dr = 1On my database that has a cost of 4 whereas the following has a cost of 6
SELECT * FROM emp
WHERE deptno = (SELECT Max(deptno) FROM emp);