how to loop through a data base for 21 button captions - mysql

Question

ok i'm banging my head on my keyboard again. With help form here so far i did get my mysql query to read the one field i wanted. but my issue is this:
Concept. A table holds button data, like caption, and other stuff for latter on. Like what TAB the button will activate on a click. <-- the later is not important right now as once i figure out this part i'm asking about i can figure it out easily i'm sure. SO. i have 21 buttons. Each button needs a caption that is located in the database. What i'm trying to figure out is how to loop through the database to get the caption for botton 1, then button two, and so on. Right now it is loading the same caption for all 21 buttons. here is my code:
Private Sub frm_MainConsole_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'PosdbDataSet.button_cat' table. You can move, or remove it, as needed.
Me.Button_catTableAdapter.Fill(Me.PosdbDataSet.button_cat)
'Procedures
Me.Show()
' Variables
Dim query As String
Dim command As MySqlCommand
Dim reader As MySqlDataReader
Dim TargetButton As Button
Try
'For button 1 through 21
dbconn()
For i As Integer = 1 To 21 Step 1
query = "select btn_caption from button_cat"
command = New MySqlCommand(query, conn)
reader = command.ExecuteReader()
reader.Read()
'btn_Cat1.Text = reader("btn_caption")
'Get the button from the controls container
TargetButton = Controls("btn_Cat" & i)
TargetButton.Text = reader("btn_caption")
reader.Close()
Next
conn.Close()
Catch ex As MySqlException
MessageBox.Show(ex.Message)
Finally
conn.Dispose()
End Try
End Sub
I appreciate ANY HELP you can give me. i learn by seeing code and manipulating it to do what i need it to do.
I'm using visual studio 2015 community and MySQL for my database and writing in Visual Basic.

Answer 1

You are rerunning your query during every loop cycle.
Do something like this:
''For button 1 through 21
dbconn()
query = "select btn_caption from button_cat"
command = New MySqlCommand(query, conn)
reader = command.ExecuteReader()
For i As Integer = 1 To 21 Step 1
reader.Read()
''btn_Cat1.Text = reader("btn_caption")
''Get the button from the controls container
TargetButton = Controls("btn_Cat" & i)
TargetButton.Text = reader("btn_caption")
Next
reader.Close()
conn.Close()
Keep in mind that this code is potentially problematic in that it assumes that there will always be 21 results returned from the database.
If you want to prevent problems if there are fewer than 21 records returned, you can do something like this:
''For button 1 through 21
dbconn()
query = "select btn_caption from button_cat"
command = New MySqlCommand(query, conn)
reader = command.ExecuteReader()
For i As Integer = 1 To 21 Step 1
If Not reader.Read() Then
''We are out of records. Exit the loop.
Exit For
End If
''btn_Cat1.Text = reader("btn_caption")
''Get the button from the controls container
TargetButton = Controls("btn_Cat" & i)
TargetButton.Text = reader("btn_caption")
Next
reader.Close()
conn.Close()
You can also rewrite this as a while loop, but you would need to re-implement your i counter.