recuentos mediante sql o delphi

[[poliburro]]

Código SQL [-]
 
 
     Select Dias, 
                Sum(Case When tiempo<='00:30:0' Then 1 Else 0 End) As MenorIgual30,
                Sum(Case When (tiempo > '00:30:0') And (tiempo <= '00:59:00') Then 1 Else 0 End) As Entre30Y60,
                Sum(Case When tiempo<='00:30:0' Then 1 Else 0 End) + 
                Sum(Case When (tiempo > '00:30:0') And (tiempo <= '00:59:00') As Total 
       From Tiempo
Group By Dias
Union 
     Select 'Total2' As Dias, 
                Sum(Case When tiempo<='00:30:0' Then 1 Else 0 End) As MenorIgual30,
                Sum(Case When (tiempo > '00:30:0') And (tiempo <= '00:59:00') Then 1 Else 0 End) As Entre30Y60,
                Sum(Case When tiempo<='00:30:0' Then 1 Else 0 End) + 
                Sum(Case When (tiempo > '00:30:0') And (tiempo <= '00:59:00') As Total 
       From Tiempo

Para que la unión funcione sin problemas Dias debe ser convertido a cadena