How i know if a report has Data in Reporting Services 2005?

I need to know if an especific report has Data, becouse i have an application which communicates with Reporting Services through a web Services and on some occasions the web services run a report and it don't have any data, in this occasions i need to do something specific, but to handle this situation, i need something to tell me when a Web Services don't found Data.

I Try to MetaData of ReportingServices but it does not work, because if a have some DataSet in one Report, it tells me all the row of all DataSet.

Can anyone tell me any other alternative?

Regards

re: How i know if a report has Data in Reporting Services 2005?

If your report is based on a table, view, table-function or query, you can do a exists() check to see if it will return a result set.

Good luck!!!

--- CK

re: How i know if a report has Data in Reporting Services 2005?

i don't understand, where i can use exist() method, remeber that i execute the report throuth a WebService, it return a bytes array that represent the reports. I used webservice.render() method. I used a webservices becouse the reports are run through a VB.net Application, so, i invoke the report through a Reporting Services's WebServices, and it return a byte array that represent the result of the reports, but the array byte alway bring byte because, the reports has a header, hence occurs bytes.