Now I am working on a project, which has to select top 25 records from a table according to one column, let's call it Num.
The case is 1) the table is not sorted by Num;
I know this part can be done by using "GROUP ORDER BY"
2) the number of the records in the table might be less than 25.
For this question, is there any way to make it in just one single SQL statement?
Thanks so much!