How to add ROW INDEX as a column to SQL SELECT query?

Question

Assume I've SQL query like this:

SELECT id, name, index(not a real column) FROM users ORDER BY rating DESC

I want to add column to selected columns that will represent the index of the record.

Example:

 id    name  rating
 1     a     4
 2     b     2
 3     c     8
 4     d     5

For this table I want to get:

 id    name  rating  index
 3     c     8       1
 4     d     5       2
 1     a     4       3
 2     b     2       4

Answer 1

Try the following to get the row_index:

set @row_num = 0; 
SELECT id,name,rating, @row_num := @row_num + 1 as row_index FROM users
ORDER BY rating desc;