How to get top most rows col into a vriable.

Question

hi,
i want to get the smallest
"Tid" greater than v_Id1
into v_b
which method i should use both are working.
1)
SELECT *
INTO v_b
FROM ( SELECT TId
FROM tt_T
WHERE TId > v_Id1
ORDER BY TId )
WHERE ROWNUM <= 1;
2)
SELECT *
INTO v_b
FROM (SELECT Tid
FROM ( SELECT TId
FROM tt_T
WHERE TId > v_Id1
ORDER BY TId )
WHERE ROWNUM <= 1);
yours sinicerely
Edited by: 944768 on Apr 28, 2013 9:35 AM

Answer 1

Hi,
944768 wrote:
i wanted to know about the correctness of my sql.
so please tel me which one is correct . or both are correct.You said both give the results you want, so both are correct.
The ways Solomon posted are also correct, and they are better, because they are faster and/or easier to maintain.
and specially about one extra bracket which i have in my 2) stmt.What do you see as the advantages and disadvantages of the 2 ways you posted?
If 2) is better than 1), wouldn't this be even better han 2)?
SELECT  *
INTO      v_b
FROM      (
         SELECT  TId
         FROM    (
                      SELECT    TId
               FROM       (
                          SELECT  TId
                          FROM    (
                                         SELECT    TId
                                FROM         tt_T
                                WHERE         TId > v_Id1
                                ORDER BY  TId
                              WHERE   ROWNUM <= 1
;Why stop at 4 sub-queries?