Oracle sorting: Sorting of null values

Background: Processing null values during sorting,

In Oracle official documents, null values are a special value type in the sorting process. By default, null values are regarded as the maximum value. That is to say, during sorting, when the null value is displayed in the sorting record, the default value is: Sorting in ascending order at the end, and vice versa.ProgramDefine it by yourself.

1. ranking first:

Select XX from student order by XX nulls first;

2. At the end

Select XX from student order by XX nulls last;

Then we can get it done!