I'm having a problem when there is no data/value is fetch during running the program, I get the following error:
Object cannot be cast from DBNull to other types.
I tried validating it using if
dr.hasrow() but I still get errors.
drqry = "SELECT max(num) FROM tbCVinfo WHERE cvno LIKE '%" & cvstr & "%'"
cmd2.CommandText = drqry
cmd2.Connection = con
Dim result As String = ""
cv = Convert.ToInt32(cmd2.ExecuteScalar())
'''''''''in this section I'm getting the error.
cv = cv + 1
If cv >= 0 And cv <= 9 Then
cn = "0001"
cn = result
cvno = cn