I need to link an access database to my visual vasic express 2008 class i have made (as been set an object orientated project) but am struggling to link the database and get it to show the information from the database through the class to the product form.
I'll attach what code i have done (i have 2 different lots as one i tried to follow another one on the internet, but just ended up confusing myself (as im a fairly basic amateur))
The one i have tried myself looks as follows:
Public Class clsItems
Dim cn As New ADODB.Connection
Dim RS As New ADODB.Recordset
Private xProduct_id As Integer
Private xName As String
Private xDescription As String
Private xPrice As Integer
Private xCategory As String
Private xMake As String
Public Sub SetProduct_id(ByVal xProduct As Integer)
xProduct_id = xProduct
End Sub
Public Function GetProduct_id() As Integer
GetProduct_id = xProduct_id
End Function
Public Sub SetName(ByVal xNew As String)
xName = xNew
End Sub
Public Function GetName() As String
GetName = xName
End Function
Public Sub SetDescription(ByVal xDesc As String)
xDescription = xDesc
End Sub
Public Function GetDescription() As String
GetDescription = xDescription
End Function
Public Sub SetPrice(ByVal xPri As Integer)
xPrice = xPri
End Sub
Public Function Getprice() As Integer
Getprice = xPrice
End Function
Public Sub SetCategory(ByVal xCat As String)
xCategory = xCat
End Sub
Public Function Getcategory() As String
Getcategory = xCategory
End Function
Public Sub SetMake(ByVal xMa As String)
xMake = xMa
End Sub
Public Function Getmake() As String
Getmake = xMake
End Function
Public Function FetchData() As Object
' GetProduct_id = RS.Fields("Product_id").Value
End Function
End ClassFor some reason we were shown to do the set and get methods like that, but don't quite see what they do.. I get to the point with the fetchdata and just end up with an error 'Expression is a value and therefore cannot be a target of an assignment'
The other attempt i have made (by following an example):
Public Class Class1
Dim cn As New ADODB.Connection
Dim RS As New ADODB.Recordset
Private xName As String
Private xDescription As String
Private xPrice As Integer
Private xCategory As String
Private xMake As String
Public Property Name() As String
Get
Name = xName
End Get
Set(ByVal Value As String)
xName = Value
End Set
End Property
Public Property Description() As String
Get
Description = xDescription
End Get
Set(ByVal value As String)
xDescription = value
End Set
End Property
Public Property Price() As String
Get
Price = xPrice
End Get
Set(ByVal value As String)
xPrice = value
End Set
End Property
Public Property Category() As String
Get
Category = xCategory
End Get
Set(ByVal value As String)
xCategory = value
End Set
End Property
Public Property Make() As String
Get
Make = xMake
End Get
Set(ByVal value As String)
xMake = value
End Set
End Property
Public Function FetchData() As Object
Name = RS.Fields("Name").Value
Description = RS.Fields("Description").Value
Price = RS.Fields("Price").Value
Category = RS.Fields("Category").Value
Make = RS.Fields("Make").Value
End Function
Private Sub Class_Initialise()
cn = New ADODB.Connection
RS = New ADODB.Recordset
cn.Provider = "Microsoft.Jet.OLEDB.3.51"
cn.ConnectionString = My.Application.Info.DirectoryPath & "\products.mdb"
cn.Open()
RS.Open("select * from [tbl_products]", cn, ADODB.CursorTypeEnum.adOpenDynamic, ADODB.LockTypeEnum.adLockBatchOptimistic)
End Sub
Public Sub New()
MyBase.New()
Class_Initialise()
End Sub
Private Sub Class_Terminate()
cn.Close()
RS.Close()
End Sub
Protected Overrides Sub Finalize()
Class_Terminate()
MyBase.Finalize()
End Sub
This one seems to work slightly more succesfully with the program only saying 'use sub finalize to free resources' (this is what i thought the bit below class terminate did)??
The form im trying to link it to so far comnprises of;
Public x As New Class1
Private Sub Label3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
x.FetchData()
txtname.Text = x.Name
txtdes.Text = x.Description
txtprice.Text = x.Price
txtprod.Text = x.Name
txtmake.Text = x.MakeWhere i thought making the text boxes on the form equal to the coinciding bits of the class would work..
If anybody can see where the problems occur or ways in which to solve them then that would be excellent and much appreciated as currently im getting very stressed trying to work this program out
Thanks
Bob
p.s. there is probably a better way to show the code on here, and i understand my codeing is probably very messy but as i say im an amateur, any advice is thankfully received