c# - Asp.net linq 查询

Question

System.Linq.IQueryable<CustomerProfile> query = 
    from usr in context.customer_profiles
    where usr.cust_email == LoginID
    select new CustomerProfile
    {
        NAME = usr.cust_name,
        CONTACT = usr.cust_contact,
        EMAILID = usr.cust_email,
        LOCATION = usr.cust_location,
        SERVICELOCATION=usr.cust_service_location,
        FAXNO=usr.cust_fax_no,
        FIRMNAME = usr.cust_firm_name,
        FIRMADDRESS = usr.cust_firm_address,
        DATEESTABLISHED = Convert.ToDateTime(((DateTime?)usr.date_of_established)),
        SIGNATURE = usr.cust_signature,
        LOGO =  usr.logo,
    };

在下一行，我遇到了“指定的转换无效”的问题。我该如何纠正这个问题？

return query.ToList().FirstOrDefault(); 

Answer 1

您在查询中将客户电子邮件与其登录 ID 进行比较。我认为这会导致转换问题，否则可能不会返回您想要的正确结果。

并使用隐式转换 (var) 而不是 IQueryable