reusing alias in SELECT reusing alias in SELECT sql sql

reusing alias in SELECT

In SQL Server or Oracle, I'd use a CTE, but since you're using MySQL, you'd use a subquery:

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;

EDIT: DOES NOT WORK. See comments.Isn't using a user variable faster in this case?

SELECT  @dr:=SUM(b.bet_win * cy.fx_rate ),  @cr:=SUM(b.bet_loss * cy.fx_rate ),   @cr+@dr as total

You can repeat the calculations in the "total" column.

SELECT     SUM(b.bet_win * cy.fx_rate) as dr,     SUM(b.bet_loss * cy.fx_rate) as cr,     SUM(b.bet_win * cy.fx_rate) + SUM(b.bet_loss * cy.fx_rate) as totalFROM ....WHERE ....