如何在linq中使用select to string？

Question

我如何使用下面的代码字符串id =（来自.....）怎么样？

using (StockProcedureDataContext stock = new StockProcedureDataContext())
            {


                id = (from m in stock.StockTools
                      from ss in stock.RefStockStatus
                      where (m.statusid == 3 || m.statusid == 5) &&
                      ss.id == m.statusid && m.id == ItemID
                      select m.id);

如何在不使用下方的情况下进行上述操作？

id = (from m in stock.StockTools
                      from ss in stock.RefStockStatus
                      where (m.statusid == 3 || m.statusid == 5) &&
                      ss.id == m.statusid && m.id == ItemID
                      select m).ToList()[0].id;

Answer 1

query.Single()   

就是这样。

Answer 2

id = (from m in stock.StockTools
                      from ss in stock.RefStockStatus
                      where (m.statusid == 3 || m.statusid == 5) &&
                      ss.id == m.statusid && m.id == ItemID
                      select m.id).FirstOrDefault();

Answer 3

如果您想要检索单个结果用户FirstOrDefault()或First()。

如果您使用First()且结果为null。它将抛出异常，但不会抛出FirstOrDefault()。

var query = (from m in stock.StockTools
                      from ss in stock.RefStockStatus
                      where (m.statusid == 3 || m.statusid == 5) &&
                      ss.id == m.statusid && m.id == ItemID
                      select m.id).FirstOrDefault();

Answer 4

只是为了变化...

query.Take(1)