System.Data.Entity不能按照MVC实体框架的预期工作 [英] System.Data.Entity not working as expected for MVC Entity Framework

问题描述

我有下面的代码片段，在i.tPersons.Any中生成错误：

I have the code snippet below which generates an error at "i.tPersons.Any" as:

'WhatWorks.Models.tPerson'不包含定义对于'Any'和没有扩展方法'Any'接受可以找到类型WhatWorks.Models.tPerson的第一个参数（您是否缺少using指令或程序集引用？）

'WhatWorks.Models.tPerson' does not contain a definition for 'Any' and no extension method 'Any' accepting a first argument of type 'WhatWorks.Models.tPerson' could be found (are you missing a using directive or an assembly reference?)

'Any'是System.Data.Entity的一个方法，所以我希望这个被拾起。我缺少什么？

'Any' is a method of System.Data.Entity so I would expect this to be picked up. What am I missing?

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using WhatWorks.Models;

namespace WhatWorks.Controllers
{
    public class InterventionController : Controller
    {
        private WhatWorksEntities db = new WhatWorksEntities();

        //
        // GET: /Intervention/

        // where parameter list only includes id
        public ActionResult Index(int id)
        {
            var model =
                    (
                        from i in db.tInterventions
                        where (i.householdID == id && !(i.tPersons.Any(t => i.householdID == id)))
                        select i
                    );

推荐答案

Any（）是一个Linq扩展方法，可以应用于IEnumerables和IQueryables。

Any() is a Linq extension method that can be applied to IEnumerables and IQueryables.

看起来你正在执行.Any（）在tPersons集合，但在谓词为任何你正在使用'我'你的案例是tInterventions的一个实例。

It looks like you are executing .Any() on the tPersons collection but in the Predicate for Any you are using 'i' which is in your case an instance of tInterventions.

所以，要么将i.householdID中的i替换为t.householdID，要么直接在tIntervension上执行Any。

So, either replace the i in i.householdID with t.householdID or execute Any on tIntervensions directly.

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