i did created an ado.net dataset and put four tables in it. i set it as the data source for my crystal report form but when i run my application i get nothing this is my code please help

Dim cryRpt10 As New ReportDocument

cryRpt10.Load(Application.StartupPath & "\test10.rpt")

Dim ds As New Mydataset

Dim SQLa As String = "SELECT table1.Num,table2.name,table3.name,table1.Date,table4.Date,table4.prise from table2 INNER JOIN (table1 INNER JOIN (table4 INNER JOIN table3 on table4.code=table3.code)on table1.Num=table4.Num) ON table2.Codef=table1.Codef where table1.Num= " & n & ""

Dim DataAdapter As New OleDbDataAdapter(SQLa, Con)