Imports System.Data.SQLite

Public Class Form1

    'Класс для хранения значений
    Public Class UsersInfo
        Public Property UserId As Integer
        Public Property Name As String

        Public Overrides Function ToString() As String
            Return Name
        End Function
    End Class

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim retList As New List(Of UsersInfo)

        Using sqlCn As New SQLiteConnection("Data source = D:\1.db")
            sqlCn.Open()

            Dim sqlCmd As SQLiteCommand = sqlCn.CreateCommand()
            sqlCmd.CommandText = "SELECT User_id, Name FROM Users"

            Using sqlRead As SQLiteDataReader = sqlCmd.ExecuteReader()
                While sqlRead.Read()
                    retList.Add(New UsersInfo() With {
                                    .UserId = sqlRead.GetInt32(0),
                                    .Name = sqlRead.GetString(1)
                                })
                End While
            End Using
        End Using

        'Связываем список
        ComboBox1.DataSource = retList
    End Sub

    'При выборе элемента кастуем к нужному типу и выводим значение ID
    Private Sub ComboBox1_SelectedValueChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedValueChanged
        MsgBox(CType(ComboBox1.SelectedValue, UsersInfo).UserId)
    End Sub

End Class