dataset

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bshaen

Member
Joined
Mar 10, 2005
Messages
19
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")
 
bshaen said:
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")
Click to expand...

For one, you didnt 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:
[VB]
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
[/VB]
 
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