Question

I’m having problem about web service method with auto increment ID.
I have a table at my Database:
tableExam

PK - IDExam - int - auto increment
---- ExamName - string
---- ExamGrade - int

then I create a web service method:

[WebMethod]
public void addExam(int IDExam, string ExamName, int ExamGrade)
{
    Exam e = new Exam{
    ExamName = ExamName,
    ExamGrade = ExamGrade};
}

then I use it to my form.
and when I click submit button, it runs:

sampleWS s = new sampleWS();
s.addExam(bla, bla, bla);

now there’s an error that told me a primary key cannot be set.

System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.Data.SqlClient.SqlException: Cannot insert explicit value for identity column in table 'tableExam' when IDENTITY_INSERT is set to OFF.
  at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
  at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
  at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning()
  at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
  at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
  at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
  at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
  at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe)
  at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
  at System.Data.Linq.SqlClient.SqlProvider.Execute(Expression query, QueryInfo queryInfo, IObjectReaderFactory factory, Object[] parentArgs, Object[] userArgs, ICompiledSubQuery[] subQueries, Object lastResult)
  at System.Data.Linq.SqlClient.SqlProvider.ExecuteAll(Expression query, QueryInfo[] queryInfos, IObjectReaderFactory factory, Object[] userArguments, ICompiledSubQuery[] subQueries)
  at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
  at System.Data.Linq.ChangeDirector.StandardChangeDirector.DynamicInsert(TrackedObject item)
  at System.Data.Linq.ChangeDirector.StandardChangeDirector.Insert(TrackedObject item)
  at System.Data.Linq.ChangeProcessor.SubmitChanges(ConflictMode failureMode)
  at System.Data.Linq.DataContext.SubmitChanges(ConflictMode failureMode)
  at System.Data.Linq.DataContext.SubmitChanges()

I try to change my web service like this:

[WebMethod]
public void addExam(string ExamName, int ExamGrade)
{
    Exam e = new Exam{
    ExamName = ExamName,
    ExamGrade = ExamGrade};
}

now it still have error:

ObjectDataSource ‘ObjectDataSourceP’ could not find a non-generic method ‘addExam’ that has parameters: IDExam, ExamName, ExamGrade.

So, what must I do to use this WS method with auto increment PK ID?

Answer 1

Changing to

sampleWS s = new sampleWS();
s.addExam(100000000, bla, bla);

and it works..

thanks for Your participate…