For retrieving or loading the report data in FlexReport, following DataSource properties of C1FlexReport should be set:

• ConnectionString
• RecordSource

To set data source:

'initialize data source
         Dim ds As DataSource = C1FlexReport1.DataSource
        ds.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\...\ComponentOne Samples\Common\C1Nwind.mdb;"
        ds.RecordSource = "Employees"

//initialize DataSource
          DataSource ds = c1FlexReport1.DataSource;
          ds.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\...\ComponentOne Samples\Common\C1NWind.mdb;";
          ds.RecordSource = "Employees";

If these properties are set, C1FlexReport initializes the data source and uses them to load the data from the database automatically. This is same as initializing data source through the code or the designer as illustrated in Step 1 of 4: Creating a Report Definition.