WHERE IN子句

Question

我在MVC3项目中工作.我浏览了一段时间并尝试了几个例子,但我无法让它工作.

我需要从OrderForm表格中获取一份记录列表,该列表位于DeptID我已经拥有的另一个列表中.

我知道我需要使用Contains()替换INSQL子句,但我能读到的每个例子都以相同的方式执行此操作

.Where(ListOfDepartments.Contains(q.DeptID))

这是我在控制器上的方法,显然不起作用:

public ActionResult ValidOrders(string installation, string orderpriority, string stockclass, string validity)
{
    int instID = System.Convert.ToInt32(installation);
    int orderpriorityID = System.Convert.ToInt32(orderpriority);
    int stockclassID = System.Convert.ToInt32(stockclass);
    string period = validity;

    try
    {
        var departments = dba.Department
                            .Where (a => a.InstID == instID);

        var valid = dba.OrderForm
            .Where(q => q.FormType == 3 
                && q.FormStatus == 2 
                && q.OrderPriority.OrderPriorityID == orderpriorityID
                && q.StockClassID == stockclassID
                && departments.Contains(q.DeptID));              

        return View(valid.ToList());
    }
    catch (Exception)
    {
        return View("Error");
    }
}

我做错了什么？

Answer 1

你需要一份清单int,而不是Department.

var departments = dba.Department
                            .Where (a => a.InstID == instID)
                            .Select(d => d.Id);//Id is a guess, it maybe another property name
                            //.ToList();