i want to save all the record to a database from a repeater on single click of button the below record are in repeater

button_click()
{
    DataTable dt = new DataTable();

    if (!dt.Columns.Contains("itemId"))
    {
        dt.Columns.Add("itemId");
    }      
    ...
    
    ...
        
    if (!dt.Columns.Contains("TotalPrice"))
    {
        dt.Columns.Add("TotalPrice");
    }
     
    if (Session["datatable"] != null)
    {
        dt = (DataTable)Session["datatable"];
    }
                     
    DataRow dr = dt.NewRow();
    
    dr[0] =  txtitemId.text()
    ...
    ...
    dr[4] =   txtTotalPrice.text()
          
    dt.Rows.Add(dr);
            
    if (Session["datatable"] == null)
    {
        Session["datatable"] = dt;
    }      
                               
    rpt.datasource=dt;
    rpt.databind();                   
}