Date Subtraction and return positive SQL value

Question

Good afternoon, I’m trying to build a Query in which I subtract two dates to return the value in days, but I only need the days that returned positive, I ran the Query that I assembled but had no return

DECLARE @POSITIVO INT

SELECT @POSITIVO = DATEDIFF(DAY, Contas_Receber.PagamentoData, Contas_Receber.Vencimento) from Contas_Receber WHERE @POSITIVO > 0

Give me the result of successfully completed Commands.

Answer 1

To know if the result will be positive the second date must be greater than the first:

SELECT DATEDIFF(DAY, cr.PagamentoData, cr.Vencimento)
  FROM Contas_Receber cr
 WHERE cr.vencimento > cr.pagamentodata