Question

我正在尝试使用linq或entityframework将两个连接表的结果绑定到我的gridview中我有

EmployeeData_Main Table (MainID, FirstName , SecondName ,LastName , DateOfBirth)
EmployeeData_Sub Table (SubID ,Address,Email,Tele,MainID-FK-)

我正在使用此查询绑定：

var queryResult = (from maindata 
    in db.EmployeeData_Main 
    join subData in db.EmployeeData_Sub 
        on maindata.MainID equals subData.MainID 
    select new 
    { 
        EmployeeData_Main = maindata, 
        EmployeeData_Sub = subData 
    })
    .ToList();

GV.DataSource = queryResult;
GV.DataBind();

我使用EmployeeData_Main.FirstName等绑定字段，但是出现了这个例外：

DataBinding: '<>f__AnonymousType0`2[[HR.EmployeeData_Main, HR, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],
[HR.EmployeeData_Sub, HR, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]' does not contain a property with the name 'MainID'.

我读了一些话题 How can I bind a query with a join to a GridView, with a Linq datasource with a business layer and data access layer ＆安培; binding linq query result to gridview

但是我仍然得到同样的例外。如何成功绑定结果

Answer 1

您的列表是匿名类型列表，仅包含两个属性：EmployeeData_Main和EmployeeData_Sub。

然后，要绑定的属性是EmployeeData_Main.MainID，它不是匿名类型的直接属性。所以你的绑定不起作用。

我不知道您是否使用了来自WebForms或WPF的GridView，但是在WPF中，您可以这样绑定它：

{ EmployeeData_Main.MainID }

或者您可以用匿名类型选择您的财产：

var queryResult = (from maindata in db.EmployeeData_Main 
                   join subData in db.EmployeeData_Sub 
                       on maindata.MainID equals subData.MainID 
   select new { MainID = maindata.MainID, EmployeeData_Main = maindata, EmployeeData_Sub = subData })
   .ToList();

Answer 2

似乎网格正在尝试查找属性queryResult.MainID，而应该查找queryResult.EmployeeData_Main.MainID。我不知道这是否真的可行。

您可以专门声明要选择的字段：

var queryResult = (from maindata in db.EmployeeData_Main 
    join subData in db.EmployeeData_Sub on maindata.MainID equals subData.MainID 
    select new { 
        maindata.MainID, 
        maindata.FirstName , 
        maindata.SecondName ,
        maindata.LastName , 
        maindata.DateOfBirth,
        subData.SubID ,
        subData.Address,
        subData.Email,
        subData.Tele,
        subData.MainID-FK-
    }).ToList();

在c＃中将查询结果绑定到Gridview

2 个答案: