dataset

[bshaen]

i would like to update my dataset record, but i dunno what the mistake i made, it cant display the output i want. can anyone point out the mistake for me , thank

 

Dim display As String

Dim ds As DataSet = New DataSet

Dim myconnection as SqlConnection

display = "SELECT * FROM Student WHERE Stdcode='ST01'"

Dim myDataAdapter As SqlDataAdapter = New SqlDataAdapter(display, myconnection)

 

myDataAdapter.Fill(ds, "Student")

[cyclonebri]

i would like to update my dataset record, but i dunno what the mistake i made, it cant display the output i want. can anyone point out the mistake for me , thank

 

Dim display As String

Dim ds As DataSet = New DataSet

Dim myconnection as SqlConnection

display = "SELECT * FROM Student WHERE Stdcode='ST01'"

Dim myDataAdapter As SqlDataAdapter = New SqlDataAdapter(display, myconnection)

 

myDataAdapter.Fill(ds, "Student")

 

For one, you didn't open your connection or new the connection object, but you may have left that code elsewhere other than this post?

Are you getting any errors? Use a Try/Catch block to catch your exceptions.

Also, your data adapter code is not going to work either. Check this out, substitute in what you need:

Sub TestDotNetCode()

       'Dim display As String
       'Dim ds As DataSet = New DataSet
       'Dim myconnection As SqlConnection
       'display = "SELECT * FROM Student WHERE Stdcode='ST01'"
       'Dim myDataAdapter As SqlDataAdapter = New SqlDataAdapter(display, myconnection)

       'myDataAdapter.Fill(ds, "Student")

       Dim constr As String = "ConnectionStringDetailsGoHERE"
       Dim sql As String = "SELECT * FROM Student WHERE Stdcode='ST01'"
       Dim cn1 As New SqlClient.SqlConnection(constr)
       Try
           cn1.Open()
           Dim cmd1 As New SqlClient.SqlCommand
           cmd1.Connection = cn1
           cmd1.CommandText = sql
           cmd1.CommandType = CommandType.Text
           Dim da1 As New SqlClient.SqlDataAdapter(cmd1)
           Dim ds1 As New DataSet("Results")
           da1.Fill(ds1)

           'see if dataset exists
           If IsNothing(ds1) Then
               MessageBox.Show("Dataset does not exist")
               Exit Sub
           End If

           'See if any data exists in the dataset:
           If ds1.Tables.Count = 0 Then
               MessageBox.Show("NO DATA FOUND!")
           Else
               'make sure that item has data before trying to retrieve it:
               If Not IsDBNull(ds1.Tables(0).Rows(0).Item(0)) Then
                   MessageBox.Show("DATA SAMPLE: " + ds1.Tables(0).Rows(0).Item(0).ToString())
               End If
           End If
       Catch ex As Exception
           'report errors:
           MessageBox.Show(ex.ToString())
       Finally
           'close connection if it exists:
           If Not IsNothing(cn1) Then
               If Not cn1.State = ConnectionState.Closed Then
                   cn1.Close()
               End If
           End If
       End Try
   End Sub