解决方案---此 ObjectContext 实例已释放,不可再用于需要连接的操作

linq一对多关联查询，结果报错，如下：

错误的代码：

using (var DbContext = new MyDbcontext()) { var users = DbContext.User.Include(x => x.DepartMent); var query = (from u in DbContext.User join d in DbContext.DepartMent on u.DepartMent.DeptId equals d.DeptId select u).ToList<User>(); return query; }正确的代码：查询的时候包含另一张表就可以了，自己煞笔了！

IQueryable<User> user = DbContext.User.Include(x => x.DepartMent); if (!string.IsNullOrEmpty(userid)) { user = user.Where(o => o.UserID == userid); } if (!string.IsNullOrEmpty(deptid)) { user = user.Where(u => u.DepartMent.DeptId == deptid); } return user.ToList();