ok risolto,
codice:
If (System.IO.File.Exists(db)) Then
            Exit Sub
        Else
            Dim create, create1 As String
            Dim eng As SqlCeEngine
            eng = New SqlCeEngine("Data Source=" + db)
            eng.CreateDatabase()
            create = ("CREATE TABLE ferie(Data nvarchar(20) PRIMARY KEY not null,Giorni nvarchar(20) not null,Altro nvarchar(30) not null,Rimanenza nvarchar(30) not null,Residuo nvarchar(30) not null)")
            ExecSql(create)
            create1 = "CREATE TABLE ore(Giorno nvarchar(20) PRIMARY KEY not null,Entrata nvarchar(20) not null,Uscita nvarchar(30) not null,Totale nvarchar(30) not null)"
            ExecSql(create1)
        End If