Read a SQL table cell value and only change a ComboBox.text without changing the ComboBox collection items - sql

Question

I'm trying to make an army list builder for a miniatures strategy game.
I'd like to know the correct method to read a SQL table cell value and to put it for each unit into a ComboBox.text field, but only into the field.
The ComBoBox collection items should not be modified (I need them to remain as it is). I just want the ComboBox.text value to be modified with the red framed value, and for each unit
For the record, currently, I read the others table informations and load them into the others ComboBoxes this way :
Private Sub TextBoxQuantitéUnités_Click(sender As Object, e As EventArgs) Handles TextBoxQuantitéUnités.Click
Dim connection As New SqlConnection("Data Source=Server;Initial Catalog=OST;Integrated Security=True")
Dim dt As New DataTable
Dim sqlquery As String
connection.Open()
sqlquery = "select * from liste1 Order By index_unité"
Dim SQL As New SqlDataAdapter(sqlquery, connection)
SQL.Fill(dt)
Dim cmd As New SqlCommand(sqlquery, connection)
Dim reader As SqlDataReader = cmd.ExecuteReader
ComboBoxNomUnités.DataSource = dt
ComboBoxNomUnités.DisplayMember = "nom_unité"
ComboBoxTypeUnités.DataSource = dt
ComboBoxTypeUnités.DisplayMember = "type_unité"
ComboBoxAbréviationUnités.DataSource = dt
ComboBoxAbréviationUnités.DisplayMember = "abréviation_unité"
ComboBoxCoutTotal.DataSource = dt
ComboBoxCoutTotal.DisplayMember = "cout_unité"
connection.Close()
End Sub
Many thanks :-)
The ComboBox.text where I want to load the cell value
The table picture with the framed value I want to load into the cell
The original ComboBox collection I want to keep
EDIT 2 :
My table structure
Your function call
A short clip of the program in order to understand my problem
As you can see, the function seems good and when I check the ComboBoxQuality text during the execution, it seems good but for some reason, it don't change...
The others Comboboxes are sync as you can see on the upper code.
Thanks in advance...
EDIT 3:
The whole code as requested :
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.Sql
Public Class FormOst
Public Function GetStringFromQuery(ByVal SQLQuery As String) As String
Dim CN = New SqlConnection("Data Source=Server;Initial Catalog=OST;Integrated Security=True")
CN.Open()
Dim StrSql As String = SQLQuery
Dim cmdReader As SqlCommand = New SqlCommand(StrSql, CN)
cmdReader.CommandType = CommandType.Text
Dim SdrReader As SqlDataReader = cmdReader.ExecuteReader(CommandBehavior.CloseConnection)
GetStringFromQuery = ""
Try
With SdrReader
If .HasRows Then
While .Read
If .GetValue(0) Is DBNull.Value Then
GetStringFromQuery = ""
Else
If IsDBNull(.GetValue(0).ToString) Then
GetStringFromQuery = ""
Else
GetStringFromQuery = .GetValue(0).ToString
End If
End If
End While
End If
End With
CN.Close()
Catch ex As Exception
MsgBox(SQLQuery, MsgBoxStyle.Exclamation, "Error")
End Try
End Function
Private Sub TextBoListeArmées_Click(sender As Object, e As EventArgs) Handles TextBoxListeArmées.Click
Dim connection As New SqlConnection("Data Source=Server;Initial Catalog=OST;Integrated Security=True")
Dim dt As New DataTable
Dim sqlquery As String
connection.Open()
sqlquery = "select [nom_unité] + ' | ' + [abréviation_unité] as Unité, index_unité, abréviation_unité, type_unité, qualité_unité, cout_unité from liste1 Order By index_unité"
Dim SQL As New SqlDataAdapter(sqlquery, connection)
SQL.Fill(dt)
Dim cmd As New SqlCommand(sqlquery, connection)
ComboBoxNomUnités.DataSource = dt
ComboBoxNomUnités.DisplayMember = "Unité"
ComboBoxNomUnités.AutoCompleteMode = AutoCompleteMode.Append
ComboBoxNomUnités.AutoCompleteSource = AutoCompleteSource.ListItems
ComboBoxTypeUnités.DataSource = dt
ComboBoxTypeUnités.DisplayMember = "type_unité"
ComboBoxAbréviationUnités.DataSource = dt
ComboBoxAbréviationUnités.DisplayMember = "abréviation_unité"
ComboBoxCoutUnité.DataSource = dt
ComboBoxCoutUnité.DisplayMember = "cout_unité"
LabelListeChargéeVisible.Enabled = True
LabelListeChargée.Visible = True
connection.Close()
End Sub
Private Sub TextBoxQuantitéUnités_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBoxQuantitéUnités.KeyPress
If Char.IsDigit(e.KeyChar) = False And Char.IsControl(e.KeyChar) = False Then
e.Handled = True
End If
End Sub
Private Sub TextBoxQuantitéUnités_TextChanged(sender As Object, e As EventArgs) Handles TextBoxQuantitéUnités.TextChanged
Try
TextBoxCoutTotal.Text = (Decimal.Parse(TextBoxQuantitéUnités.Text) * Decimal.Parse(ComboBoxCoutUnité.Text)).ToString()
Catch ex As Exception
End Try
End Sub
Private Sub ButtonEffacer_Click(sender As Object, e As EventArgs) Handles ButtonEffacer.Click
TextBoxQuantitéUnités.Text = ""
ComboBoxNomUnités.Text = ""
ComboBoxTypeUnités.Text = ""
ComboBoxQualitéUnités.Text = ""
ComboBoxAbréviationUnités.Text = ""
ComboBoxCoutUnité.Text = ""
TextBoxCoutTotal.Text = ""
End Sub
Private Sub LabelListeChargéeVisible_Tick(sender As Object, e As EventArgs) Handles LabelListeChargéeVisible.Tick
LabelListeChargée.Visible = False
LabelListeChargéeVisible.Enabled = False
End Sub
Private Sub ComboBoxNomUnités_SelectionChangeCommitted(sender As Object, e As EventArgs) Handles ComboBoxNomUnités.SelectionChangeCommitted
Try
'' TextBoxCoutTotal.Text = (Decimal.Parse(ComboBoxCoutUnité.SelectedItem.ToString) * Decimal.Parse(TextBoxQuantitéUnités.Text)).ToString
ComboBoxQualitéUnités.Text = GetStringFromQuery("SELECT qualité_unité FROM liste1 ORDER BY index_unité")
Catch ex As Exception
End Try
End Sub
End Class

Answer 1

Function for retrieving your data via sql query
Public Function GetStringFromQuery(ByVal SQLQuery As String) As String
Dim CN As New SqlConnection("Data Source=Server;Initial Catalog=OST;Integrated Security=True")
CN.Open()
Dim StrSql As String = SQLQuery
Dim cmdReader As SqlCommand = New SqlCommand(StrSql, CN)
cmdReader.CommandType = CommandType.Text
Dim SdrReader As SqlDataReader = cmdReader.ExecuteReader(CommandBehavior.CloseConnection)
'SdrReader = cmdReader.ExecuteReader
GetStringFromQuery = ""
Try
With SdrReader
If .HasRows Then
While .Read
If .GetValue(0) Is DBNull.Value Then
GetStringFromQuery = ""
Else
If IsDBNull(.GetValue(0).ToString) Then
GetStringFromQuery = ""
Else
GetStringFromQuery = .GetValue(0).ToString
End If
End If
End While
End If
End With
CN.Close()
Catch ex As Exception
MsgBox(SQLQuery, MsgBoxStyle.Exclamation, "Error")
End Try
End Function
Retrieve data and put into your combo box text
ComboBox.Text = GetStringFromQuery("Enter Sql Query here")

Answer 2

Your sql query problem.
Your query select everything and you suppose to return the UOM that relate to your item
Private Sub ComboBoxNomUnités_SelectionChangeCommitted(sender As Object, e As EventArgs) Handles ComboBoxNomUnités.SelectionChangeCommitted
Try
Dim Product as string = ComboBoxNomUnités.Text
ComboBoxQualitéUnités.Text = GetStringFromQuery("SELECT qualité_unité FROM liste1 Where Nom_Unité = '" & Product & "'")
Catch ex As Exception
End Try
End Sub