title: There is already an object named 'AspNetRoles' in the database when trying to update with Entity Framework
body: <p>I'm receiving this error with my ApplicationDbContext database when trying to update with Entity Framework. I've googled, tried fixes here on SO, but all to no avail. Currently I'm just deleting my database each time i make a change, but once I deploy, that will not be an option.<br>
  Here's the error:</p>
  
  <blockquote>
    <p>PM> update-database -context applicationdbcontext
    System.Data.SqlClient.SqlException: There is already an object named 'AspNetRoles' in the database.
       at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action<code>1 wrapCloseInAction)
       at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
       at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean&amp; dataReady)
       at System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async, Int32 timeout, Boolean asyncWrite)
       at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource</code>1 completion, Boolean sendToPipe, Int32 timeout, Boolean asyncWrite, String methodName)
       at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
       at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.Execute(IRelationalConnection connection, String executeMethod, IReadOnlyDictionary<code>2 parameterValues, Boolean closeConnection)
       at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.ExecuteNonQuery(IRelationalConnection connection, IReadOnlyDictionary</code>2 parameterValues)
       at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.ExecuteNonQuery(IEnumerable`1 migrationCommands, IRelationalConnection connection)
       at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
       at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateDatabase(String targetMigration, String contextType)
       at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.&lt;>c__DisplayClass0_1.&lt;.ctor>b__0()
       at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
    ClientConnectionId:b2628a7e-7024-471e-9be2-2d0b25f3ad3c
    Error Number:2714,State:6,Class:16
    There is already an object named 'AspNetRoles' in the database.</p>
  </blockquote>
  
  <p>I have not used <code>context.Database.EnsureCreated()</code> anywhere in my code.</p>