错误“操作失败，因为表 Y 上已存在名称为 X 的索引或统计信息答案

【问题标题】：Error "operation failed because an index or statistics with name X already exists on table Y错误“操作失败，因为表 Y 上已存在名称为 X 的索引或统计信息
【发布时间】：2016-11-23 16:29:33
【问题描述】：

我正在尝试将网站部署到 Azure Web Apps。 IDE：Visual Studio 2015/U3。

网站：ASP.NET MVC 4 网站。我尝试使用 Publish 通过 VS 将站点部署到 Azure Web App。

浏览器出错：

“/”应用程序中的服务器错误。

操作失败，因为名为“IX_OwnerId”的索引或统计信息已存在于表“dbo.Auctions”中。

说明：在执行当前 Web 请求期间发生未处理的异常。请查看堆栈跟踪以获取更多信息有关错误的信息以及它在代码中的来源。

异常详细信息： System.Data.SqlClient.SqlException：操作失败，因为名称为“IX_OwnerId”的索引或统计信息表“dbo.Auctions”上已存在。

来源错误：

在执行过程中产生了一个未处理的异常当前的网络请求。有关原产地和位置的信息可以使用下面的异常堆栈跟踪来识别异常。

堆栈跟踪：

[SqlException (0x80131904): The operation failed because an index or statistics with name 'IX_OwnerId' already exists on table 'dbo.Auctions'.]
   System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +2442634
   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +5766568
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +285
   System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +4162
   System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async, Int32 timeout, Boolean asyncWrite) +948
   System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) +286
   System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +286
   System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.<NonQuery>b__0(DbCommand t, DbCommandInterceptionContext`1 c) +10
   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.NonQuery(DbCommand command, DbCommandInterceptionContext interceptionContext) +356
   System.Data.Entity.Internal.InterceptableDbCommand.ExecuteNonQuery() +103
   System.Data.Entity.Migrations.DbMigrator.ExecuteSql(MigrationStatement migrationStatement, DbConnection connection, DbTransaction transaction, DbInterceptionContext interceptionContext) +109
   System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsInternal(IEnumerable`1 migrationStatements, DbConnection connection, DbTransaction transaction, DbInterceptionContext interceptionContext) +83
   System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsWithinTransaction(IEnumerable`1 migrationStatements, DbTransaction transaction, DbInterceptionContext interceptionContext) +65
   System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsWithinNewTransaction(IEnumerable`1 migrationStatements, DbConnection connection, DbInterceptionContext interceptionContext) +155
   System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsInternal(IEnumerable`1 migrationStatements, DbConnection connection, DbInterceptionContext interceptionContext) +346
   System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsInternal(IEnumerable`1 migrationStatements, DbConnection connection) +509
   System.Data.Entity.Migrations.<>c__DisplayClass30.<ExecuteStatements>b__2e() +19
   System.Data.Entity.SqlServer.<>c__DisplayClass1.<Execute>b__0() +10
   System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Func`1 operation) +189
   System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Action operation) +78
   System.Data.Entity.Migrations.DbMigrator.ExecuteStatements(IEnumerable`1 migrationStatements, DbTransaction existingTransaction) +194
   System.Data.Entity.Migrations.DbMigrator.ExecuteStatements(IEnumerable`1 migrationStatements) +7
   System.Data.Entity.Migrations.DbMigrator.ExecuteOperations(String migrationId, VersionedModel targetModel, IEnumerable`1 operations, IEnumerable`1 systemOperations, Boolean downgrading, Boolean auto) +828
   System.Data.Entity.Migrations.DbMigrator.AutoMigrate(String migrationId, VersionedModel sourceModel, VersionedModel targetModel, Boolean downgrading) +559
   System.Data.Entity.Migrations.DbMigrator.Upgrade(IEnumerable`1 pendingMigrations, String targetMigrationId, String lastMigrationId) +403
   System.Data.Entity.Migrations.DbMigrator.UpdateInternal(String targetMigration) +445
   System.Data.Entity.Migrations.<>c__DisplayClassc.<Update>b__b() +13
   System.Data.Entity.Migrations.DbMigrator.EnsureDatabaseExists(Action mustSucceedToKeepDatabase) +422
   System.Data.Entity.Migrations.DbMigrator.Update(String targetMigration) +78
   System.Data.Entity.MigrateDatabaseToLatestVersion`2.InitializeDatabase(TContext context) +108
   System.Data.Entity.Internal.<>c__DisplayClassf`1.<CreateInitializationAction>b__e() +76
   System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action) +60
   System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization() +357
   System.Data.Entity.Internal.LazyInternalContext.<InitializeDatabase>b__4(InternalContext c) +7
   System.Data.Entity.Internal.RetryAction`1.PerformAction(TInput input) +110
   System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action`1 action) +198
   System.Data.Entity.Internal.LazyInternalContext.InitializeDatabase() +73
   System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +28
   System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +53
   System.Data.Entity.Internal.Linq.InternalSet`1.GetEnumerator() +15
   System.Data.Entity.Infrastructure.DbQuery`1.System.Collections.Generic.IEnumerable<TResult>.GetEnumerator() +53
   System.Linq.Enumerable.ToDictionary(IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer) +146
   System.Linq.Enumerable.ToDictionary(IEnumerable`1 source, Func`2 keySelector) +89
   OnlineAuction.Controllers.HomeController.Index(Int32 CategoryId, String SearchKeyword) in C:\Users\Chico\Desktop\DIPLOMA PROJECT\DIPLOMA PROJECT\Проект\задав вопрос о оунерАди\delete — копия\OnlineDonors\Controllers\HomeController.cs:26
   lambda_method(Closure , ControllerBase , Object[] ) +146
   System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +14
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +182
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27
   System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +28
   System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +10
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +32
   System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +58
   System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +225
   System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +34
   System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +24
   System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +99
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
   System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +14
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +36
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   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() +9765121
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

我看了这篇文章： Unhandled Exception after Upgrading to Entity Framework 4.3.1

我试图删除Auctions 表上的重复项。这是我在Up() 类的Up() 方法中创建的Auctions 和Users 表：

public partial class InitialCreate : DbMigration
{
    public override void Up()
    {
        CreateTable(
            "dbo.Auctions",
            c => new
                {
                    Id = c.Long(nullable: false, identity: true),
                    Title = c.String(nullable: false, maxLength: 160),
                    Description = c.String(nullable: false),
                    CurrentPrice = c.Double(nullable: false),
                    StartTime = c.DateTime(nullable: false),
                    EndTime = c.DateTime(nullable: false),
                    OwnerId = c.Int(nullable: false),
                    WinningBidId = c.Int(),
                    CategoryId = c.Int(nullable: false),
                })
            .PrimaryKey(t => t.Id)
            .ForeignKey("dbo.Users", t => t.OwnerId)
            .ForeignKey("dbo.Bids", t => t.WinningBidId)
            .ForeignKey("dbo.Categories", t => t.CategoryId)
            .Index(t => t.OwnerId)
            .Index(t => t.WinningBidId)
            .Index(t => t.CategoryId);                   
     }
 }

起初我删除了这一行：

 .ForeignKey("dbo.Users", t => t.OwnerId)

并重新部署了网站。还是一样的错误。

然后我从Auctions 表创建中删除了.Index(t => t.OwnerId)。发生同样的错误。

其他信息：

在 Global.asax 的 Application_Start() 方法中，我有这一行：

 System.Data.Entity.Database.SetInitializer(new System.Data.Entity.MigrateDatabaseToLatestVersion<AuctionDataContext, Configuration>());

在 Web.config 的 <configSections> 中：

<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />

我的初始化在Configuration 类中：

   public class Configuration : DbMigrationsConfiguration<OnlineAuction.Models.Entities.AuctionDataContext>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = true;
        }

        protected override void Seed(AuctionDataContext context)
        { 
            ***All my initializations go here 
        }
    }

问题：如何解决？

【问题讨论】：

标签： asp.net-mvc entity-framework azure ef-code-first azure-web-app-service

【解决方案1】：

据我所知，ForeignKeyIndexConvention Code First 约定可能会导致为模型中任何外键的列创建索引。您可以尝试在 DbContext.OnModelCreating 方法上删除此约定。

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    //your code  

    //remove ForeignKeyIndexConvention  
    modelBuilder.Conventions.Remove<ForeignKeyIndexConvention>();
}

【讨论】：