entity-framework – 如何限制web api返回的列？

概述如何限制web api&amp ;;返回的列数实体框架？ 我会尽可能多地欣赏信息,因为我还是新手;) 我的控制器： //GET: api/Creditors public IQueryable<Creditor> GetCreditors() { return db.Creditors; } 我的课： using System;using System.C 如何限制web API&amp ;;返回的列数实体框架？
我会尽可能多地欣赏信息,因为我还是新手;)

我的控制器：

//GET: API/Creditors    public I@R_419_5962@able<Creditor> GetCreditors()    {        return db.Creditors;    }

我的课：

using System;using System.Collections.Generic;using System.ComponentModel.DataAnnotations;using System.linq;using System.Web;namespace PurchaSEOrders.Models{public class Creditor{    [Key]    public int CreditorID { get; set; }    [MaxLength(10,ErrorMessage = "Maximum of 10 characters")]    public string CRKEY { get; set; }    [display(name = "Business name")]    [MaxLength(40,ErrorMessage = "Maximum of 40 characters")]    public string Businessname { get; set; }    [MaxLength(40,ErrorMessage = "Maximum of 40 characters")]    public string Address { get; set; }    [MaxLength(40,ErrorMessage = "Maximum of 40 characters")]    public string City { get; set; }    [MaxLength(4,ErrorMessage = "Maximum of 4 characters")]    public string State { get; set; }    [MaxLength(4,ErrorMessage = "Maximum of 4 characters")]    public string Postcode { get; set; }    [MaxLength(15,ErrorMessage = "Maximum of 15 characters")]    public string Phone { get; set; }    [MaxLength(15,ErrorMessage = "Maximum of 15 characters")]    public string Fax { get; set; }    [MaxLength(60,ErrorMessage = "Maximum of 60 characters")]    public string Email { get; set; }    [MaxLength(60,ErrorMessage = "Maximum of 60 characters")]    public string Website { get; set; }    [MaxLength(30,ErrorMessage = "Maximum of 30 characters")]    public string Contactname { get; set; }    [MaxLength(15,ErrorMessage = "Maximum of 15 characters")]    public string ABN { get; set; }    [display(name = "Registered for GST")]    public bool RegisteredForGST { get; set; }}}

目前返回：

[{"CreditorID":1,"CRKEY":"test1","Businessname":"test1","Address":"7 Smith Street","City":"Melbourne","State":"VIC","Postcode":"3000","Phone":null,"Fax":null,"Email":null,"Website":null,"Contactname":null,"ABN":"null","RegisteredForGST":true},{"CreditorID":2,"CRKEY":"test2","Businessname":"test2","Address":"10 Smith Street","City":"SYDNEY","State":"NSW","Postcode":"2000","RegisteredForGST":true}]

这是我想要的结果(只有“CreditorID”和“Businessname”)：

[{"CreditorID":1,"Businessname":"test1"},"Businessname":"test2"}]

解决方法 在您的问题中,您正在显示查询的Json输出,因此我假设您正在从JavaScript发出GET请求.当您使用I@R_419_5962@able作为API方法的返回值类型时,您应该能够利用WebAPI提供的OData支持,以便您可以发出OData查询以仅选择所需的列.这个 this article有关OData支持的更多细节.

首先,JavaScript方面,假设j@R_419_5962@易于回答：

$.get('API/Creditors?$select=CreditorID,Businessname',onSuccess)

所需的列名称在$select参数的逗号分隔列表中指定. (onSuccess是一个你将定义的回调函数,它将传递从API返回的数据.有关详细信息,请参阅jQuery documentation.)

在服务器端,您可能需要从ODataController而不是APIController派生控制器,您需要将[@R_419_5962@able]或[Enable@R_419_5962@]属性添加到GetCreditors()方法,具体取决于您使用的WebAPI版本.

如果您发现需要从ODataController继承以使其工作,那么还需要添加一些配置,即配置OData端点.为此,您将需要类似于以下内容的代码：

public static class WebAPIConfig{    public static voID Register(httpConfiguration config)    {        ODataModelBuilder builder = new ODataConventionModelBuilder();        builder.EntitySet<Creditor>("Creditors");        config.MapODataServiceRoute(            routename: "ODaTaroute",routePrefix: null,// or "API" ?            model: builder.GetEdmModel());    }}

在您的Web启动代码中的某处(例如Application_Start),您需要按如下方式调用它：

GlobalConfiguration.Configure(WebAPIConfig.Register);

根据你如何设置你的项目,后面的一些配置可能没有必要,因为它已经完成,但我想我会提到它的好处.有关详细信息,请查看this page.

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