Connection Setup Overview
Most every report, or .rpt file, will reference a database. To refresh data in The Report Viewer, the software will need to be able to find this database as it is referenced in the report.
This reference is often in the form of a Data Source Name (DSN), a file path to an Excel spreadsheet (.xls file), a file path to a Character Separated Values database (.csv file), or a reference to a custom database driver.
When you try to refresh the report in The Report Viewer, the software looks for this data source or database.
If the data source or database is found, all goes as planned.
If there is a problem, you may needlessly get prompted for a username and password, get a connection error, or even have the report fail to open. This simply means that some work will be required to get the report to refresh correctly from the database.
General Troubleshooting of the Database Connections
The general way to get the connection setup and working correctly, is to setup the database connections on the PC with The Report Viewer installed the same way as they are set up on the PC that is used to create the report. This means the Data Source Name must exactly match the Data Source Name in the report, and paths to database files referenced in the report must exist. There are ways to override these items, but it's generally easier to get it working first without overriding the database settings.