tdykstra / contosouniversityefcore Goto Github PK

Hi,

I followed this very educational tutorial: Creating a complex data model - EF Core with ASP.NET Core MVC tutorial (5 of 10).
https://docs.microsoft.com/et-ee/aspnet/core/data/ef-mvc/complex-data-model

After running the command "dotnet ef database update" at CLI, I am getting an error: "There is already an object named 'Course' in the database", (see below).

The app is working until then, but when I want to change column attributes as described in paragraph "The Column attribute", I am getting an error form browser: :SqlException: Invalid column name 'FirstName'. System.Data.SqlClient.SqlCommand+<>c.b__107_0(Task result).

I would like to learn more. Thanks in advance!

CLI Error Description:

Microsoft Windows [Version 6.3.9600]
(c) 2013 Microsoft Corporation. All rights reserved.

C:\Users\User\Documents\visual studio 2017\Projects\ContosoUniversity\ContosoUni
versity>dotnet ef database update

Build succeeded.
0 Warning(s)
0 Error(s)

Time Elapsed 00:00:07.21
System.Data.SqlClient.SqlException: There is already an object named 'Course' in the database.
at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObj ect stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async, Int32 timeout, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSou rce1 completion, Boolean sendToPipe, Int32 timeout, Boolean asyncWrite, String
methodName)
at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.Execute(I
RelationalConnection connection, String executeMethod, IReadOnlyDictionary2 par ameterValues, Boolean closeConnection) at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.ExecuteNo nQuery(IRelationalConnection connection, IReadOnlyDictionary2 parameterValues)
at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor
.ExecuteNonQuery(IEnumerable`1 migrationCommands, IRelationalConnection connecti
on)
at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String
targetMigration)
at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateD
atabase(String targetMigration, String contextType)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.<>c_
_DisplayClass0_1.<.ctor>b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execu
te(Action action)
ClientConnectionId:b1bd24a3-87e2-4d93-b1c1-006b37c31f53
Error Number:2714,State:6,Class:16
There is already an object named 'Course' in the database.
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