DataTable and Dataset error [* Resolved *] but why???

[steve_rm]

Hello,

I am practicing writing code using the dataset and datatable. But l keep getting these errors in the code. Can't understand what is going wrong. the code is listed below. I can sort of understand what the errors are, but not sure how to solve them. When l check the text book for the corrrect syntax, everything is corrrect

Code for using the datatable

Imports System.Data
Imports System.Data.SqlClient

Public Class MyCustomers


    Inherits System.Web.UI.Page
    Protected WithEvents DataGrid1 As System.Web.UI.WebControls.DataGrid
    Protected WithEvents Button1 As System.Web.UI.WebControls.Button

#Region " Web Form Designer Generated Code "

    'This call is required by the Web Form Designer.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

    End Sub

    Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
        'CODEGEN: This method call is required by the Web Form Designer
        'Do not modify it using the code editor.
        InitializeComponent()
    End Sub

#End Region

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'Create objects
        Dim cnnstr As String = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=southwind;Data Source=steves-pc\netsdk"
        Dim daCustomers As New SqlDataAdapter("Select * From Customers", cnnstr)
        Dim dtCustomers As New DataTable("Customers") 'error here

        daCustomers.Fill(dtCustomers) 'error here

        'Execute
        DataGrid1.DataSource = dtCustomers
        DataBind()

        'Clean up
        daCustomers.Dispose()
        dtCustomers.Dispose()

    End Sub
End Class

Code for using the dataset

Imports System.Data
Imports System.Data.SqlClient

Public Class MyCustomers


    Inherits System.Web.UI.Page
    Protected WithEvents DataGrid1 As System.Web.UI.WebControls.DataGrid
    Protected WithEvents Button1 As System.Web.UI.WebControls.Button

#Region " Web Form Designer Generated Code "

    'This call is required by the Web Form Designer.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

    End Sub

    Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
        'CODEGEN: This method call is required by the Web Form Designer
        'Do not modify it using the code editor.
        InitializeComponent()
    End Sub

#End Region

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'Create objects
        Dim cnnstr As String = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=southwind;Data Source=steves-pc\netsdk"
        Dim cnn As New SqlConnection(cnnstr)
        Dim daCustomers As New SqlDataAdapter("Select * From Customers", cnnstr)
        Dim dsCustomers As New DataSet("NorthWind")'error here

        'Execute
        daCustomers.Fill(dsCustomers,"Customers")'Error here
        DataGrid1.DataSource = dsCustomers.tables("Customers")
        DataBind()

        'Clean up
        dsCustomers.Dispose()
        daCustomers.Dispose()

    End Sub
End Class

I hope someone can tell me what is wrong with this code.

Thanks for your time in helping me

Steve

[steve_rm]

Can no one not help me with this problem.

Steve

[Fishcake]

What errors do you get exactly?

Also you say there's an error with the line

Dim dtCustomers As New DataTable("Customers") 'error here

I can't see how there's an error there any more details?

[steve_rm]

Thanks for your reply fishcake.

I have done everything, but still getting the same error. The error says "Value of type chapter8.dataset cannot be converted to system.data.sqlclient.sqlconnection". Well Chapter8 is the name of my project. Could there be a problem here

imports system.data 
imports system.data.sqlclient 


Dim cnnstr As String = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=southwind;Data Source=steves-pc\netsdk" 
        Dim sqlconn As New SqlConnection(cnnstr) 
        Dim cmd As New SqlCommand("Select * From Customers", sqlconn) 
        Dim daCustomers As New SqlDataAdapter(cmd) 
        Dim dsCustomers As New DataSet() 

        daCustomers.Fill(dsCustomers, "Customers") 'Error - Value of type chapter8.DataSet cannot be converted to System.data.dataset

Thanks for you help.

Steve

[Fishcake]

I can't see whats wrong with that last snippet, i even just cut and pasted it (changing database connection of course) and it worked fine from here, as follows..

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        'Dim cnnstr As String = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=southwind;Data Source=steves-pc\netsdk"
        Dim sqlconn As New SqlConnection("********")
        Dim cmd As New SqlCommand("Select * From Players", sqlconn)
        Dim daCustomers As New SqlDataAdapter(cmd)
        Dim dsCustomers As New DataSet
 
        daCustomers.Fill(dsCustomers, "Customers") 'No Error
        DataGrid1.DataSource = dsCustomers.Tables("Customers")
        DataGrid1.DataBind()
 
        'Clean up
        dsCustomers.Dispose()
        daCustomers.Dispose()
    End Sub

Sorry couldn't be of more use.

[steve_rm]

Hello,

Could the problem be something to do with the way the project is set up.

If l remove the imports system.data.sqlClient
l don't get the error.

This is very strange, hope someone help me.

Thanks for your time.

Steve

[steve_rm]

Hello,

I started a new vb ASP project, and did the same for the dataset and datatable. Both are working now. But l don't know what the problem was before, with my original project.

code for dataset

Dim cnnstr As String = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=southwind;Data Source=steves-pc\netsdk"
        Dim cnn As New SqlConnection(cnnstr)
        Dim daCustomers As New SqlDataAdapter("Select * From Customers", cnn)
        Dim dsCustomers As New DataSet("Customers")

        'Execute
        daCustomers.Fill(dsCustomers, "Customers")
        DataGrid1.DataSource = dsCustomers
        DataGrid1.DataBind()

        'Clean-up
        daCustomers.Dispose()
        dsCustomers.Dispose()

code for the datatable

Dim cnnstr As String = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=southwind;Data Source=steves-pc\netsdk"
        Dim daCustomers As New SqlDataAdapter("Select * From Customers", cnnstr)
        Dim dtCustomers As New DataTable("My Table")

        'Execute
        daCustomers.Fill(dtCustomers)
        DataGrid1.DataSource = dtCustomers
        DataBind()

        'Clean-up
        dtCustomers.Dispose()
        daCustomers.Dispose()

I still think it has something to do with how the original project was setup. But not sure. If you have any ideas can you tell me.

Thanks,

Steve