当选择组合框项时，将项列表显示到CheckListBox

我有一个windows窗体应用程序在表单中，我有一个组合框和一个列表框。当我选择comboBox时，我想显示用户可以在checkListBox中检查的项目列表，我弄清楚了如何将数据绑定到comboBox部分，但我不确定如何显示值列表，以便用户可以在checkListBox中进行选择。假设我有一个项目列表，存储在一个SQL数据库调用item_table，我怎么能显示它到checkListBox根据当我从comboBox选择?代码供参考将不胜感激。由于

例如

假设用户从组合框中选择"Amy"，则checkListBox将显示一个项目列表"item1, item2, item3, item4"。

当用户从组合框中选择"Brad"时，它将显示一个项目列表:"item2, item5, item10

等

这是我的数据库表(SQL)服务器

user_Detail
     In my user_Detail table , I have 10 user and each of them have a primary key (userId) and a column (userName);
item_Detail
    In my item_Detail table, I have 20 items and they also have a primary key (itemId) and a column (itemName) 

在sql控制台中，我内部连接两个表(我不确定我是否需要在代码中的SqlCommand中做同样的事情)

下面是我在控制台中使用的sql命令。

      select
          user_Detail.userId,
          user_Detail.userName,
          item_Detail.itemId,
          item_Detail.itemName
      from
          item_Detail
       INNER JOIN user_Detail ON user_Detail.userId = item_Detail.itemId

我的代码

namespace Test {
    public partial class MainForm: Form {
        SqlConnection myConn;
        SqlCommand myCommand;
        SqlDataReader myReader;
        SqlDataAdapter myDa;
        DataTable dt;
        DataSet ds = new DataSet();
        public MainForm() {
            InitializeComponent();
            // loadComboBox
            loadComboBox();
        }
         //Connect to my db to fetch the data when the application load
        private void loadComboBox() {
     myConn = new SqlConnection("Server = localhost; Initial Catalog= dbName; Trusted_Connection = True");
            string query = "Select * from user_Detail";
            myCommand = new SqlCommand(query, myConn);
            try {
                myConn.Open();
                myReader = myCommand.ExecuteReader();
                string s = "<------------- Select an item ----------->";
                itemComboBox.Items.Add(s);
                itemComboBox.Text = s;
                while (myReader.Read()) {
                    //declare a string
                    object userId = myReader[userId"];
                    object userName = myReader["userName"];
                    //my comboBox named userComboBox
                    userComboBox.Items.Add(userName.ToString());
                }
            } catch (Exception ex) {
                MessageBox.Show(ex.Message);
            }
        }
        //Display some items here (this is my checkListBox
     private item_checkListBox(Object sender, EventArgs e){

     }

     private void load_item(){


    }

private void loadComboBox() {
        myConn = new SqlConnection("Server = localhost; Initial Catalog=dbName; Trusted_Connection = True");
        string query = "Select * from user_Detail";
        myCommand = new SqlCommand(query, myConn);
        try {
            myConn.Open();
            myReader = myCommand.ExecuteReader();
            string s = "<------------- Select an item ----------->";
            itemComboBox.Items.Add(s);
            itemComboBox.Text = s;
            while (myReader.Read()) {
                //declare a string
                string userId = myReader["userId"].toString();
                string userName = myReader["userName"].toString();
                //my comboBox named userComboBox
                userComboBox.Items.Add(userName);
            }
            myConn.Close();
        } catch (Exception ex) {
            MessageBox.Show(ex.Message);
        }
    }

userComboBox.SelectedIndexChanged += (o,ev) => { ChangeCheckListItems(); };

private void ChangeCheckListItems(){
    myCheckListBox.Items.Clear();
    string selectedText = userComboBox.Text;
    switch(selectedText){
          case "Amy":
          AddItemsForAmy();
          break;
          case "Brad":
          AddItemsForBrad();
          break:
    }
}

private void AddItemsForAmy(){
    myConn = new SqlConnection("Server = localhost; Initial Catalog=dbName         Trusted_Connection=true;"
    string query = "Select * from item_Detail where itemId % 2 = 0"
    myCommand = new SqlCommand(query, myConn);
    try{
      myConn.Open();
      myReader = myCommand.ExecuteReader();
      while(myReader.Read()){
      string itemName = myReader["itemName"].toString();
      myCheckListBox.Items.Add(itemName);
      }
      myConn.Close();
    }
    catch(SqlExcetion ex){
           MessageBox.Show(ex.Message);
    }
}