[英]How can i use select to string in linq?
我怎么能使用下面的代码字符串id =(从.....)如何?
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);
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;
query.Single()
而已。
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();
如果要检索单个结果用户FirstOrDefault()或First() 。
如果使用First()
且结果为null,它将引发异常,但不会引发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();
只是为了多样性...
query.Take(1)
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.