SQL ORDER BY AS变量

Question

I have an sql query sorta like this:

SELECT

.....
price

..... AS distance

ORDER BY case
  ...

my question is, how can i use the calculated distance as a sorting element?

Answer 1

It's unclear for me what "distance" is in the question's query and why you put case in oeder by.

In general, you can mention field within ORDER BY clause either by its alias or by its number within the select clause. You can put some logic into ORDER BY as well

  select A,
         B as MyB,
         C - Z, -- <- Field #3: (A - #1, B - #2, C - Z - #3, D + F + G - #4 etc)
         D + F + G
    from MyTable
order by MyB asc,       -- <- by alias
         3 desc,        -- <- by field's number
         D + F + G asc, -- <- by some logic, here it's just copy + paste
         case           -- <- by some logic designed for ORDER BY only
           when (A > B + C) then
             1
           when (A > B)  then
             2
           else    
             3
         end desc