linq - linq EnumerableQuery?

Question

任何想法如何检索 EnumerableQuery 中的值我想检索“Y”或 Null 以创建、更新、删除列，就像我对 Read 列所做的一样，但不是返回“Y”或 NULL，而是返回为 EnumerableQuery，并且我不知道怎么做

from a in MenuFunctions
where a.Scd == 'R' && a.Ise == 'Y'
select new{
    a.Mcd,
    Read = a.Ise,
    Create = (from b in MenuFunctions
                where b.Pcd== a.Mcd && b.Psc == a.Scd && b.Ise=='Y' && b.Scd =='C'
                select b.Ise),
    Update = (from b in MenuFunctions
                where b.Pcd== a.Mcd && b.Psc == a.Scd && b.Ise=='Y' && b.Scd =='U'
                select b.Ise),
    Delete = (from b in MenuFunctions
                where b.Pcd== a.Mcd && b.Psc == a.Scd && b.Ise=='Y' && b.Scd =='D'
                select b.Ise),
}

结果

Answer 1

from a in MenuFunctions
where a.Scd == 'R' && a.Ise == 'Y'
select new{
    a.Mcd,
    Read = a.Ise,
    Create = (from b in MenuFunctions
                where b.Pcd== a.Mcd && b.Psc == a.Scd && b.Ise=='Y' && b.Scd =='C'
                select b.Ise).firstOrDefault() == null ? "N" : "Y",
    Update = (from b in MenuFunctions
                where b.Pcd== a.Mcd && b.Psc == a.Scd && b.Ise=='Y' && b.Scd =='U'
                select b.Ise).firstOrDefault() == null ? "N" : "Y",
    Delete = (from b in MenuFunctions
                where b.Pcd== a.Mcd && b.Psc == a.Scd && b.Ise=='Y' && b.Scd =='D'
                select b.Ise).firstOrDefault() == null ? "N" : "Y",
}

好的，我现在想通了，我需要使用firstOrDefault从中返回值并添加 == null ？"N" : "Y"，我还解决了列内的​​空值 :) 但不确定是否有更好的 linq 方法来执行与此相同的功能