无法从网格视图将数据更新到数据库

我的数据库中有两个表.

INV_HEAD和DN_HEAD

表格在下面的链接中给出

http://www.freeimagehosting.net/uploads/7dda8cd2c7.jpg [
在网格视图中，我想输入LR_NO和LR_DT的数据(其中为null)

当我更新数据时，我得到的错误数据无法在两个表中进行更新.
谁能帮我更新数据..

无需在DN_HEAD中的2个表中进行更新就足够了


在这里输入我的代码

I have two tables in my data base .

INV_HEAD and DN_HEAD

tables are given in below link

http://www.freeimagehosting.net/uploads/7dda8cd2c7.jpg[^]]


I have combined two tables by "inner join" and show the data in grid view where LR_NO is null.

in the grid view I want to enter data of LR_NO and LR_DT (where null)

when i am updating data I am getting error data can not be updated in two tables.
can any one help me to update data ..

no need to update in 2 table update in DN_HEAD is enough


HERE MY CODE

public partial class Form2 : Form
    {
        SqlConnection con;
        SqlDataAdapter da1;
        SqlCommandBuilder cb;
        DataSet ds;
        
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            con = new SqlConnection("User Id=sa;Password=123;database=amar");
           
 da1 = new SqlDataAdapter("SELECT dbo.INV_HEAD.INV_NO, dbo.INV_HEAD.INV_DT, dbo.DN_HEAD.DN_NO, dbo.DN_HEAD.DN_DT, dbo.DN_HEAD.LR_NO, dbo.DN_HEAD.LR_DT FROM dbo.INV_HEAD INNER JOIN dbo.DN_HEAD ON dbo.INV_HEAD.DN_NO = dbo.DN_HEAD.DN_NO where LR_DT IS NULL", con);
            
            ds = new DataSet();
            cb = new SqlCommandBuilder(da2);
            da1.Fill(ds, "DN_HEAD,INV_HEAD");
            
            dataGridView1.DataSource = ds.Tables["DN_HEAD,INV_HEAD"];
         }

        private void button1_Click(object sender, EventArgs e)
        {
            da1.Update(ds, "DN_HEAD,INV_HEAD");
            
            MessageBox.Show("data saved");
        }