Async client

manosm · March 13, 2012, 9:51pm

I am building an async client, and there is a problem when i call the IDataAbstractService_Async methods, where when i call the invoke_getdata, i would like to pass parametes with filters to the server.
I suppose it has to be done on the invoke_getdata, in order to have the server fetch the proper data, and get them back with the retrieve_getdata.

manosm · March 13, 2012, 10:36pm

Is this the right way to implement the above mentioned question, or do i have to implement it with a different way

Manos

elenap · March 15, 2012, 8:42am

Hello,

In order to use GetData method with parameters you should define SQL statement for DataTable in schema with necessary parameters, then add these parameters in TableRequestInfoArray


 with aTableRequestInfoArray.Add do
     begin
         IncludeSchema := True;
         MaxRecords := -1;
         with Parameters.Add do begin
            Name:='ParamName';
            Value:=ParamValue;
         end;
      end;

and call fServ.Invoke_GetData(aTableList, aTableRequestInfoArray);

You could also use SQLGetData method with direct SQL query in order to retrieve only proper data

Best regards.

manosm · March 15, 2012, 7:34pm

Thank you for the reply, I’l test both ways, and let you know in case of problem

Best regards

manosm · March 15, 2012, 11:15pm

Hello again

I have used Invoke_GetData with TableRequestInfoV5, and not the SqlGetData, which i believe not to be a safe one, especially because I am building a data farm, with about 5-8 sql servers, and about some hundreds of same schema databases.
On the other hand, i don’t want to use parameters in my datatable schema, so i would’t have to reconstruct those sql every time i need a knew parameter.
So i believe with TableRequestInfoV5, i could do the job.
I invoke the Invoke_GetData, construct the TableRequestInfoV5 parametes, and i got a timer to invoke the Retrieve_GetData, in order to display the actual data, but i don’t know how to process the TRObinarymemorystream witch is returned.
I could use some of your help. I could provide source code, to be more helpful.

Best Regards

elenap · March 16, 2012, 9:59am

Hello,

You could load data from returned Binary like this:
fData:=fserv.Retrieve_GetData();

ClientDataModule.DataStreamer.Initialize(fData,aiRead);
try

// load schema
ClientDataModule.DataStreamer.ReadDataset(
ClientDataModule.DataStreamer.DatasetNames[0],
ClientDataModule.tbl_TableName, true, false);
ClientDataModule.tbl_TableName.InitializeDataTable;
// load records
ClientDataModule.DataStreamer.ReadDataset(
ClientDataModule.DataStreamer.DatasetNames[0],
ClientDataModule.tbl_TableName, false, true, false);
finally
ClientDataModule.DataStreamer.Finalize;
end;

Hope this helps

manosm · March 16, 2012, 10:56pm

Hello again, and thank you once more for the effort

I tried to load the returned binary with the datasteamer, but doesn’t work as expected.
Seems like, when i Retrieve_Getdata, the DA reloads all data to binary, ignoring the allready invoke_getdata function. I have checked the Invoke_getdata with TableRequestInfoV5 and the wherechause and works fine.
I have attached my source code in order to investigate.

hope my source, helps you

ps i have allready used the dtmBRClient.bdsPatient.ReadDataset(fData,aTable,True) in my code without any success.

Thanks in advance

manosm · March 16, 2012, 11:01pm

Back again, i found the problem in my code.
It was wrong initialization for the cdspatient dataset

Thank you again.