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));
    }

}

Christian Graus写道:

Christian Graus wrote:

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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