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c# - 无效的列名 C#

转载 作者:行者123 更新时间:2023-12-03 19:33:39 27 4
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我对 C# 和 Visual Studio MVC 很陌生,正在开发一个简单的项目,我需要实现一个可以通过表单发布的评论页面(我尚未实现)。这是我的问题,我不断收到“无效的列 ID”错误。我一直在网上查找所有答案,但没有找到任何可以解决我的问题的内容。我来自 Java,所以有些概念对我来说并不是很明显,特别是自从我昨天开始以来。

这是我的背景:

namespace MonLivredor.Models {
public class CommentaireContext: DbContext {
public CommentaireContext() {}
public IDbSet < Commentaire > Liste {
get;
set;
}
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
Database.SetInitializer < CommentaireContext > (null);
base.OnModelCreating(modelBuilder);
}
}
}

这是我的 Controller :

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

namespace MonLivredor.Controllers
{
public class CommentaireController : Controller
{
private CommentaireContext context = new CommentaireContext();
// GET: Commentaire
public ActionResult Commentaire()
{

Commentaire com1 = new Commentaire("Jacky", "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="83c9e2e0e8fac3e4eee2eaefade0ecee" rel="noreferrer noopener nofollow">[email protected]</a>", "Bonjour je m'apelle Jacky et j'aime le C#");
Commentaire com2 = new Commentaire("Bobby", "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="51133e33332811363c30383d7f323e3c" rel="noreferrer noopener nofollow">[email protected]</a>", "Bonjour je m'apelle Bobby et je deteste le Java");

if (context.Liste.Count() == 0)
{
context.Liste.Add(com1);
context.Liste.Add(com2);
context.SaveChanges();
return View(context);
}
else
{
return View(context);
}
}

型号:

namespace MonLivredor.Models
{
[Table("Commentaires")]
public class Commentaire
{
[Key]
public int ID { get; set; }
[Required]
public String Nom { get; set; }
public String Mail { get; set; }
public String Message { get; set; }
public DateTime date;
public int i = 0;

public Commentaire(String nom, String mail, String message)
{
date = DateTime.Now;
this.Nom = nom;
this.Mail = mail;
this.Message = message;
ID = i;
i++;
}

public Commentaire()
{
date = DateTime.Now;
}


}
}

在我看来,我只想能够看到这些消息:

@model MonLivredor.Models.CommentaireContext
<h1>Commentaires</h1>

<tr>
@foreach (var com in Model.Liste)
{
<td>
<a href="mailto:com.Mail">@com.Nom @com.date</a>
<p>@com.Message</p>
</td>

}
</tr>

抱歉,代码很乱,我一直在为此抓狂,答案可能很愚蠢。当我收到错误时,我会被重定向到以下行的 View 页面:

@foreach (var com in Model.Liste)

出现错误“无效的列名称 ID”。

堆栈跟踪:

[SqlException (0x80131904): Invalid column name 'ID'.]
System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +2442126
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +5736904
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +628
System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +3731
System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() +58
System.Data.SqlClient.SqlDataReader.get_MetaData() +89
System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +379
System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds, Boolean describeParameterEncryptionRequest) +2026
System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) +375
System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +53
System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) +240
System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) +41
System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior) +12
System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.<Reader>b__c(DbCommand t, DbCommandInterceptionContext`1 c) +9
System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch(TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed) +72
System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext) +356
System.Data.Entity.Internal.InterceptableDbCommand.ExecuteDbDataReader(CommandBehavior behavior) +166
System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior) +12
System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) +37

[EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for details.]
System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) +112
System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute(ObjectContext context, ObjectParameterCollection parameterValues) +744
System.Data.Entity.Core.Objects.<>c__DisplayClass7.<GetResults>b__6() +97
System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction(Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) +288
System.Data.Entity.Core.Objects.<>c__DisplayClass7.<GetResults>b__5() +154
System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Func`1 operation) +189
System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption) +279
System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0() +11
System.Data.Entity.Internal.LazyEnumerator`1.MoveNext() +45
System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +381
System.Linq.Enumerable.ToList(IEnumerable`1 source) +58
MonLivredor.Controllers.CommentaireController.Commentaire() in C:\Users\Bob\documents\visual studio 2015\Projects\MonLivredor\MonLivredor\Controllers\CommentaireController.cs:26
lambda_method(Closure , ControllerBase , Object[] ) +62
System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +14
System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +157
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27
System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState) +22
System.Web.Mvc.Async.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult) +29
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +32
System.Web.Mvc.Async.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d() +50
System.Web.Mvc.Async.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() +225
System.Web.Mvc.Async.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__32(IAsyncResult asyncResult) +10
System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +34
System.Web.Mvc.Async.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() +26
System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +100
System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +13
System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +36
System.Web.Mvc.Controller.<BeginExecute>b__15(IAsyncResult asyncResult, Controller controller) +12
System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +22
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26
System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +21
System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9744373
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

感谢您的帮助

最佳答案

您不应该使用 DbContext直接在 View 中将类作为模型。您的 Controller 操作应该负责使用 DbContext 从数据库获取数据。并将其传递给 View 。您所做的方式不会提供 Model View Controller 模式的好处,而是滥用 MVC 模式。 View 应该只知道将从 Controller 接收什么类型的模型,现在数据获取代码在您看来不是正确的方法。

您做错了几件事,首先, View 中的模型声明应该是 List<MonLivredor.Models.Commentaire> ,因此将其更改为:

@model List<MonLivredor.Models.Commentaire>
<h1>Commentaires</h1>

<tr>
@foreach (var com in Model)
{
<td>
<a href="mailto:com.Mail">@com.Nom @com.date</a>
<p>@com.Message</p>
</td>

}

然后在你的操作中有很多问题,你需要从数据库查询结果,如果没有结果,那么在添加这2个项目后,你可以再次从数据库查询结果:

public ActionResult Commentaire()
{
IQueryable<Commentaire> result = context.Liste;
if (!result.Any())
{

context.Liste.Add(new Commentaire("Jacky", "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="4c062d2f27350c2b212d2520622f2321" rel="noreferrer noopener nofollow">[email protected]</a>", "Bonjour je m'apelle Jacky et j'aime le C#"));
context.Liste.Add(new Commentaire("Bobby", "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="a7e5c8c5c5dee7c0cac6cecb89c4c8ca" rel="noreferrer noopener nofollow">[email protected]</a>", "Bonjour je m'apelle Bobby et je deteste le Java"));
context.SaveChanges();

}

return View(result.ToList());
}

您还需要将模型构造函数更改为:

public Commentaire(int id,String nom, String mail, String message)
{
date = DateTime.Now;
this.Nom = nom;
this.Mail = mail;
this.Message = message;
ID = id;
}

并从 Controller 传递 ID 值或另一个更好的选项是使 ID由数据库自动生成的列值,可以使用@bilpor来完成答案,但更新模型后,您必须运行迁移以使用新更改更新表。

关于c# - 无效的列名 C#,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/41999172/

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