genbruge alias i SELECT

I SQL Server eller Oracle ville jeg bruge en CTE, men da du bruger MySQL, ville du bruge en underforespørgsel:

SELECT dr, cr, cr + dr as total 
FROM (
    SELECT 
         SUM(b.bet_win * cy.fx_rate ) as dr, 
         SUM(b.bet_loss * cy.fx_rate ) as cr
    FROM ....
    WHERE ....) t;