vb.net/mysql show more then 1 row in TextBox - mysql

Question

I just started messing around with Visual basic (vb.net) and am trying to show more then 1 database row in a TextBox, so far I have this:
Private Sub foobox_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Dim conn As MySqlConnection
conn = New MySqlConnection
conn.ConnectionString = connStr
Try
conn.Open()
Catch myerror As MySqlException
MsgBox("No connection")
End Try
Dim myAdaptor As New MySqlDataAdapter
Dim sqlquery = "SELECT * FROM foo ORDER BY id DESC"
Dim myCommand As New MySqlCommand()
myCommand.Connection = conn
myCommand.CommandText = sqlquery
myAdaptor.SelectCommand = myCommand
Dim myData As MySqlDataReader
myData = myCommand.ExecuteReader()
If myData.HasRows Then
myData.Read()
Viewer.Text = myData("foo1") & myData("foo2")
End If
myData.Close()
conn.Close()
End Sub
which connects to a database successfully but but it only outputs 1 row, how can I get it to output more?

Answer 1

You need a loop reading data and storing line after line in a StringBuilder.
Then, when exiting from the reading loop set the Text property of your textbox
Dim sb as StringBuilder = new StringBuilder()
While myData.Read()
sb.AppendLine(myData("foo1") & myData("foo2"))
End While
Viewer.Text = sb.ToString
and, of course, your textbox should have the MultiLine property set to True
Apart from this direct answer to your question, your code should be changed to dispose the connection and the datareader after use, I have also removed the DataAdapter because is not needed here
Using conn = New MySqlConnection(connStr)
Try
conn.Open()
Catch myerror As MySqlException
MsgBox("No connection")
End Try
Dim sqlquery = "SELECT * FROM foo ORDER BY id DESC"
Dim myCommand As New SqlCommand(sqlquery, conn)
Using myData = myCommand.ExecuteReader()
Dim sb as StringBuilder = new StringBuilder()
While myData.Read()
sb.AppendLine(myData("foo1") & myData("foo2"))
End While
Viewer.Text = sb.ToString
End Using
End Using

Answer 2

You need some kind of loop. I would also use the Using statement to ensure that all unmanaged resources are disposed even in case of an exception(it also closes the connection):
Using conn As New MySqlConnection(connStr)
Using myCommand As New MySqlCommand("SELECT * FROM foo ORDER BY id DESC", conn)
Try
conn.Open()
Using myData = myCommand.ExecuteReader()
If myData.HasRows Then
While myData.Read()
Dim line = String.Format("{0}{1}{2}",
myData.GetString(myData.GetOrdinal("foo1")),
myData.GetString(myData.GetOrdinal("foo1")),
Environment.NewLine)
viewer.Text &= line
End While
End If
End Using
Catch ex As Exception
MessageBox.Show(ex.ToString())
End Try
End Using
End Using
However, if you want to show multiple records i would recommend a ListBox instead. It's more efficient with many items and it also separates them logical from each other.
( just replace viewer.Text &= line with ListBox1.Items.Add(line) )