I have started a form application using visual studio 2010 express, vb programming. I'm using Access as my database.

My goal is to have ComboBox1 display a ProjectID and ComboBox2 display a TestNumber. Once the Test Number is selected I want my textboxes in the form to display fields from the row that the selected Test Number is in.

I have 2 tables set up right now "Projects" and "TestData". The "Projects" table has a [ProjectID] field, the remaining fields are just misc. project data. The "TestData" table also has the [ProjectID] field, and then the [TestNumber] field, then the remaining fields are misc. data.

Filling [ProjectID] in textbox1 is easy, in the properties I select DataSource from the Projects table, display [ProjectID] field. Where I'm having troubles is ComboBox2 displaying the TestNumber from the other "TestData" table. If I select that field, it fills the ComboBox with EVERY TestNumber there is. So for Project 1 there is a test 1... over 500 projects, that combobox lists 500 Test 1's, no way to tell what project it belongs to...

How do I make ComboBox2 only display Test Numbers that pertain to the Project number selected in ComboBox1?

Using this code I can get it to work:

Dim ProjectNo, SQLString As String
Dim dtTableData As New DataTable()
Dim dbDataAdapter As OleDbDataAdapter
Dim ConnectionString As String = ("Provider = Microsoft.Jet.OLEDB.4.0;" & "Data Source = Database.MDB")
ProjectNo = ComboBox1.Text
SQLString = ("Select * FROM TestData WHERE ProjectID = " & "'" & ProjectNo & "'" & "")
dbDataAdapter = New OleDbDataAdapter(SQLString, ConnectionString)
ComboBox2.DataSource = dtTableData

I also imported system.data.oledb

Problem with this code is it will only filter data in ComboBox 2 but when you make your selection from ComboBox2 it won't activate the row so none of my databinding textboxes fill anymore. Before the code/query is ran it fills up the textboxes perfectly after every selection I just have no idea what project that report number belongs to because the whole field is displayed in the dropdown. I can fill the form with ComboBoxes and they display the corresponding row data because I use a "datasource" instead of textbox "databindings" but I don't want to use 20 comboboxes as my entry form...

I'm new and all my coding has come from reading countless forums and watching youtube videos. Any help would be greatly appreciated as this one little step has drove me nuts!

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