如何在linq中添加另一个项目? [英] How to add another item in linq?
问题描述
我正在使用linq to sql.在我的程序的开头,从SQL数据库中加载了一个列表.然后,用户可以添加其他项目.项目不会立即保存,因此无法在数据库表中使用InsertOnSubmit
方法.我必须将项目保存在主要的linq变量中,并且当用户按下保存"按钮时,必须将其保存.
我尝试了多种方法来在linq变量中添加项目,但没有一种有效.
谁能帮我吗?
Hi,
I''m using linq to sql. In my program at the beginning, a list is loaded from the SQL database. Then user can add another items. Items are not saved immediately therefore I can not use InsertOnSubmit
method in my DB table. I have to save item in the main linq variable and when the user pushes SAVE button it has to be saved.
I tried many ways to add an item in linq variable but none of them worked.
Can anyone help me?
static public void add(UserLoginData item)
{
try
{
item.Order = GetNewOrder();
UserLoginData[] item_array=new UserLoginData[]{item};
var usersA = from c in users
orderby c.Order
select c;
var usersB = from c in item_array
select c;
var usersC= usersA.Union(usersB);//related to this error: Local sequence cannot be used in LINQ to SQL implementation of query operators except the Contains() operator.
MainListUsers = from c in usersA
orderby c.Order
select c;
ListRefresh();
}
catch (Exception ex)
{
Logging.Log.Report(ex.Message, "Error", new System.Diagnostics.StackFrame(true));
}
}
这是一个SQL数据库.为什么需要使用LINQ?
It''s a SQL database. Why do you need to use LINQ ?
因此,Linq-to-SQL的用途是什么?
Therefore what is Linq-to-SQL for?
推荐答案
这是一个SQL数据库.为什么需要使用LINQ?
It''s a SQL database. Why do you need to use LINQ ?
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