使用LINQ to SQL和defaultifempty()的问题 [英] Problem using LINQ to SQL and defaultifempty()

问题描述

Hiya

运行代码时出现以下错误.代码是:

Hiya

I am getting the following error when running my code. The code is:

var list= (from list in dc.tblList
                          where list.listID == listID
                          select (list.aspnet_User.aspnet_Membership.Email)).DefaultIfEmpty();

if (list != null)
        {
             //insert code here
        }

会产生以下错误:

无法格式化节点"OptionalValue"以执行为SQL.

有人可以帮忙吗?！

Which produces the following error:

Could not format node ''OptionalValue'' for execution as SQL.

Can anyone help?!

推荐答案

尝试一下:

try this :

var list= (from list in dc.tblList
                          where list.listID == listID
                          select (list.aspnet_User.aspnet_Membership.Email)).First();

我使用了.count ();获取记录的数量，然后获取条件为if>的if语句. 0 ...解决了它.可能更简单的方法，但这就是我所使用的方法！

I used a .count(); to get the amount of records, and then an if statement with the condition if > 0 do... which has solved it. Probably easier ways but that''s the one I''ve gone with!

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