As everybody knows if I need to sort out the result of a SELECT I have to include at the end of query the 'ORDER BY' keyword.
Following an example :
select NUMERI_GRAD from grad where sect_id = 101 and grade_type= 'FI' order by NUMERI_GRAD desc;
Output : 99,92,91,etc.
However if I need to limit the result of the previous query , how can I get the right result ?
We can include the ROWNUM keyword, can't we ?
Yes, but pay special attention to the result :
select NUMERI_GRAD from grad where sect_id = 101 and grade_type = 'FI' and rownum <4 order by NUMERI_GRAD desc;
Output : 99,88,77,etc.
We have a problem. The "NUMERI_GRAD" code isn't well ordered. This is why the 'ROWNUM' keyword is applied before the 'ORDER BY' .
However a handy option to solve the problem could be the following :
select NUMERI_GRAD from (select NUMERI_GRAD from grad where sect_id = 101 and grade_type= 'FI' order by NUMERI_GRAD desc) where rownum < 4;
This query looks like an inline-view, doesn't it ?
See you in my next blog.
Byeeee
