Question

我得到这样的错误：指定的LINQ表达式包含对与不同上下文关联的查询的引用。

var employee = new ApplicationDbContext().Employee;
var otherTable = new OtherDbContext().OtherTable;

var returnValue = (from e in employee
                        join o in otherTable on e.Id equals o.Id
                        select new
                        {
                            e.Name,
                            e.Address,
                            o.Others
                        });

任何解决方案？谢谢！

Answer 1

您应该通常实例化您的DBContext，而不是指定表/模型。例如：

 private ApplicationDBContext db = new ApplicationDbContext();

然后选择您是否还要使用LINQ或Raw SQL。我相信你对SQL更熟悉，因为你提到加入表，为什么不使用它呢？ Here's a tutorial on how to use Raw SQL.

If you still insist in using LINQ and involve join, here's a good reference for it.

Answer 2

List<Employee> empList = new ApplicationDbContext().Employee.ToList();
List<OtherTable> othrList= new OtherDbContext().OtherTable.ToList();

var returnValue = (from e in empList 
                        join o in othrList on e.Id equals o.Id
                        select new
                        {
                            e.Name,
                            e.Address,
                            o.Others
                        });

试试这个会起作用.....

（Linq / Lambda）使用2个DBContext连接2个或更多表

2 个答案: