请教一下,EF框架中Lambda表达式中,如果实现 ISNULL(sum(name),0)

假设Number是table表里的一列。
var query = from table in
(from table in table
select new {
Number,
Dummy = "x"
})
group table by new { table.Dummy } into g
select new {
Result= ((Int32?)g.Sum(p => p.Number) ?? (Int32?)0)
}