我有桌子:
游客
Tourist_ID
2.Name
Extra_Charges
1.Extra_Charge_ID
2.Description
3.Amount
Toutist_Extra_Charges
1.Tourist_ID - foreign key
2.Extra_Charge_ID - foreign key
所以我有一个带有ID的列表,我想用特定的id来记录游客的名字和他所有的额外费用(他们的描述和金额)。 因为我有很多很多关系,这是我的代码,它给了我以下例外:
List<int> reTouristID = new List<int>();
reTouristID.Add(86);
reTouristID.Add(87);
for (int i=0;i<reTouristID.Count;i++)
{
var db2 = new excursionEntities3();
var tourist = db2.Tourist.Include("EXTRA_CHARGES").SingleOrDefault(t => t.Tourist_ID==reTouristID[i]);
if (tourist != null)
{
lblproba.Text += "Name " + tourist.Name_kir;
}
var extrachargess = tourist.EXTRA_CHARGES.Select(e => new {e.Extra_Charge_Description,e.Amout});
foreach (var extra in extrachargess)
{
lblproba.Text += "Des: " + extra.Extra_Charge_Description;
lblproba.Text += "AMM:" + extra.Amout;
}
}
答案 0 :(得分:2)
就在这一行:
SingleOrDefault(t => t.Tourist_ID==reTouristID[i])
引擎盖下,reTouristID[i]
是一个方法get_Item,它是EF无法转换为SQL的众多CLR方法之一(它应该如何?)。解决方法很简单:
var index = reTouristID[i];
var tourist = db2.Tourist.Include("EXTRA_CHARGES")
.SingleOrDefault(t => t.Tourist_ID == index);
答案 1 :(得分:0)
for (int i = 0; i < Data.Count(); i++)
{
var d = Data[i].Field;
var check = context.Data.Where(p => p.field.Contains(d)).ToList();
if (check.Count == 0)
{
// Do Your Stuff for Existing Data
}
else
{
// Do Your Stuff for Non-Existing Data
}
}