使用LINQ进行CRUD

# 创建linq to sql类
private void search_Click(object sender, EventArgs e)
{
    linqtosqlDataContext linq = new linqtosqlDataContext(connStr);
    var result = from stu in linq.Students
                 select stu.StuName;
    listBox1.DataSource = result;
}

private void insert_Click(object sender, EventArgs e)
{
    linqtosqlDataContext linq = new linqtosqlDataContext(connStr);
    Student stu = new Student();
    stu.StuName = "kyle";
    linq.Students.InsertOnSubmit(stu);
    linq.SubmitChanges();
}

private void delete_Click(object sender, EventArgs e)
{
    linqtosqlDataContext linq = new linqtosqlDataContext(connStr);
    var result = from stu in linq.Students
                 where stu.StuName == "kyle"
                 select stu;
    linq.Students.DeleteAllOnSubmit(result);
    linq.SubmitChanges();
}

private void update_Click(object sender, EventArgs e)
{
    linqtosqlDataContext linq = new linqtosqlDataContext(connStr);
    var result = from stu in linq.Students
                 where stu.StuName == "kyle"
                 select stu;
    foreach(var s in result)
    {
        s.StuName = "bob";
        linq.SubmitChanges();
    }
}

private void search2_Click(object sender, EventArgs e)
{
    linqtosqlDataContext linq = new linqtosqlDataContext(connStr);
    var result = from stu in linq.Students
                 from coz in linq.Stu_Coz
                 where stu.StuId == czo.SId
                 select stu;
}