DeleteOnSubmit - 未找到行或更改

Question

//SelectUtilitiesCheckbox is bound to a complete list of the Utilitie_companies table 
foreach (ListItem x in SelectUtilitiesCheckBox.Items) 
{ 
    Select_Utility SU = rows.Where(r => r.Utility_Id == Convert.ToInt32(x.Value)).FirstOrDefault(); 
    bool initialValue = SU != null; 

    if (x.Selected == true && initialValue == false) 
    { 
     // New qualification added so save it 
     Select_Utility NewSelectUtility = new Select_Utility(); 
     NewSelectUtility.WorkId = tempWorkSiteId; 
     NewSelectUtility.Utility_Id = System.Convert.ToInt32(x.Value); 

     context.Select_Utilities.InsertOnSubmit(NewSelectUtility); 
    } 
    else if (x.Selected == false && initialValue == true) 
    { 
     // Removed old qualification so remove it in the database 
     context.Select_Utilities.DeleteOnSubmit(SU); 
    } 
} 

context.SubmitChanges(); 

我的Q是 - 使用LINQ - 將在提交作品很好，但是當我嘗試使用deleteOnSubmit我得到一個

ERROR: ChangeConflictEception was unhandled by user code - Row not found or changed.

當它到達context.submit但在上下文中使用breakpoit'Su'.Select_Utilities.DeleteOnSubmit（SU）;包含刪除正確的記錄

任何想法爲什麼？

Answer 1

感謝...

System.Data.Linq.ChangeConflictException: Row not found or changed

我已經解決了這個問題。

問題是：DB中的一個字段可以爲空，但在DBML文件中不能爲空。更改記錄以適應問題。