Question

如您所见，我正在创建一个包含一个主键的新类，我将数据库重新设置为重新创建它，但

public class CustomerContracts
{
    [Key, Column("ItemId")]  //This change the name of the column when you are using migration.  If you have a form created already, you have to change the connection in the for to aim the new column name.  

    public int ItemId { get; set; }

    public string Description { get; set; }

    public string CustomerRef { get; set; }


    public int ContractTypeId { get; set; }

    public DateTime StartDate { get; set; }

    public DateTime EndDate { get; set; }

    public bool isActive { get; set; }
    [DecimalPrecision(18, 2)]
    public decimal Price { get; set; }

}

但是当我尝试更新数据库时，我收到以下错误。

指定'-Verbose'标志以查看应用于目标数据库的SQL语句。应用显式迁移：[201804260855058_firstmigration]。应用显式迁移：201804260855058_firstmigration。 System.Data.SqlClient.SqlException（0x80131904）：为表'CustomerContracts'指定了多个标识列。每个表只允许一个标识列。在System.Data.SqlClient.SqlConnection.OnError（SqlException异常，Boolean breakConnection，Action 1 wrapCloseInAction) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action 1 wrapCloseInAction）在System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning（TdsParserStateObject stateObj，Boolean callerHasConnectionLock，Boolean asyncClose）在System.Data.SqlClient.TdsParser.TryRun（RunBehavior runBehavior，SqlCommand cmdHandler，SqlDataReader dataStream，BulkCopySimpleResultSet bulkCopyHandler，TdsParserStateObject stateObj，Boolean＆amp; dataReady）在System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds（String methodName，Boolean async，Int32 timeout，Boolean asyncWrite）在System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery（TaskCompletionSource 1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.<NonQuery>b__0(DbCommand t, DbCommandInterceptionContext 1 c）在System.Data.Entity.Infrastructure.Interception.InternalDispatcher 1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func 3操作，TInterceptionContext interceptionContext，Action 3 executing, Action 3执行）在System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.NonQuery（DbCommand命令，DbCommandInterceptionContext interceptionContext）在System.Data.Entity.Internal.InterceptableDbCommand.ExecuteNonQuery（）在System.Data.Entity.Migrations.DbMigrator.ExecuteSql（MigrationStatement migrationStatement，DbConnection连接，DbTransaction事务，DbInterceptionContext interceptionContext）在System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.ExecuteSql（MigrationStatement migrationStatement，DbConnection连接，DbTransaction事务，DbInterceptionContext interceptionContext） at System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsInternal（IEnumerable 1 migrationStatements, DbConnection connection, DbTransaction transaction, DbInterceptionContext interceptionContext) at System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsWithinTransaction(IEnumerable 1 migrationStatements，DbTransaction transaction，DbInterceptionContext interceptionContext） at System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsWithinNewTransaction（IEnumerable 1 migrationStatements, DbConnection connection, DbInterceptionContext interceptionContext) at System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsInternal(IEnumerable 1 migrationStatements，DbConnection connection，DbInterceptionContext interceptionContext）在System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsInternal（IEnumerable 1 migrationStatements, DbConnection connection) at System.Data.Entity.Migrations.DbMigrator.<>c__DisplayClass32.<ExecuteStatements>b__30() at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.<>c__DisplayClass1.<Execute>b__0() at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func 1操作）在System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute（Action操作）在System.Data.Entity.Migrations.DbMigrator.ExecuteStatements（IEnumerable 1 migrationStatements, DbTransaction existingTransaction) at System.Data.Entity.Migrations.DbMigrator.ExecuteStatements(IEnumerable 1 migrationStatements）在System.Data.Entity.Migrations.Infrastructure.MigratorBase.ExecuteStatements（IEnumerable 1 migrationStatements) at System.Data.Entity.Migrations.DbMigrator.ExecuteOperations(String migrationId, VersionedModel targetModel, IEnumerable 1个操作，IEnumerable 1 systemOperations, Boolean downgrading, Boolean auto) at System.Data.Entity.Migrations.DbMigrator.ApplyMigration(DbMigration migration, DbMigration lastMigration) at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.ApplyMigration(DbMigration migration, DbMigration lastMigration) at System.Data.Entity.Migrations.DbMigrator.Upgrade(IEnumerable 1 pendingMigrations，String targetMigrationId，String lastMigrationId）在System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.Upgrade（IEnumerable`1 pendingMigrations，String targetMigrationId，String lastMigrationId）在System.Data.Entity.Migrations.DbMigrator.UpdateInternal（String targetMigration）在System.Data.Entity.Migrations.DbMigrator。＆lt;＆gt; c__DisplayClasse.b__d（）在System.Data.Entity.Migrations.DbMigrator.EnsureDatabaseExists（Action mustSucceedToKeepDatabase）在System.Data.Entity.Migrations.Infrastructure.MigratorBase.EnsureDatabaseExists（Action mustSucceedToKeepDatabase）在System.Data.Entity.Migrations.DbMigrator.Update（String targetMigration）在System.Data.Entity.Migrations.Infrastructure.MigratorBase.Update（String targetMigration）在System.Data.Entity.Migrations.Design.ToolingFacade.UpdateRunner.RunCore（）在System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run（） ClientConnectionId：8aa18649-614e-4be4-a46d-fb780984d59f 错误号码：2744，州：2，班级：16 为表'CustomerContracts'指定的多个标识列。每个表只允许一个标识列。

为什么我会收到此错误。正如你所看到的，我只使用一个键，我也没有重命名它（当我删除数据库时它是一个新表）。任何帮助表示赞赏。

这是我的迁移我在删除数据库之后删除了文件夹，但仍然将信息上下移动。

 public partial class firstmigration : DbMigration
    {
        public override void Up()
        {
            DropPrimaryKey("dbo.CustomerContracts");
            AddColumn("dbo.CustomerContracts", "ItemId", c => c.Int(nullable: false, identity: true));
            AddPrimaryKey("dbo.CustomerContracts", "ItemId");
            DropColumn("dbo.CustomerContracts", "TeamId");
        }

        public override void Down()
        {
            AddColumn("dbo.CustomerContracts", "TeamId", c => c.Int(nullable: false, identity: true));
            DropPrimaryKey("dbo.CustomerContracts");
            DropColumn("dbo.CustomerContracts", "ItemId");
            AddPrimaryKey("dbo.CustomerContracts", "TeamId");
        }
    }

Answer 1

试试这个：

public override void Up()
{
    DropPrimaryKey("dbo.CustomerContracts");
    DropColumn("dbo.CustomerContracts", "TeamId"); // Drop this first
    AddColumn("dbo.CustomerContracts", "ItemId", c => c.Int(nullable: false, identity: true));
    AddPrimaryKey("dbo.CustomerContracts", "ItemId");
}

无法创建多个ID，但我只有一个

1 个答案: