使用linq从C#中的列表中的SQL返回层次结构 [英] Return hierarchy from sql in lists in c# using linq

问题描述

我在sql中有一个表，该表具有三列(ID，名称，ParentID)，每列都有很多记录.现在，我想要的是从ParrentId中获取所有的学习成果，并将其包含在三个视图中.

I have table in sql which have three columns (ID, Name, ParentID) and each columns have many records. Now what i want is to get all hiearachy from ParrentId, to include it in three view.

可以通过一些不错的LINQ解决方案来解决吗?

Is that can be solved with some nice LINQ solution?

我之前尝试过的方法是使用其中一个是孩子的List-s集，但是出现问题的原因是某些孩子列表也可以有更多孩子.

What i try before is to use set of List-s which one of those is child, but problem occur cause some child list can also have more childs under.

我需要使用linq代码:

I need this with linq code:

    List<Menu> hList = new List<Menu>();

var m1 = new Menu();

var m2 = new Menu();
var m3 = new Menu();

hList.AddRange(new List<Menu>() { m1, m2, m3});

但是在实际示例中，当然不会只有3个子变量.

but of course in real example it wouldnt be just 3 child var-s.

感谢任何帮助和建议！

推荐答案

public void FillMenu(EntityCollection menuList, List<Menu> hList, int? parentMenuId)
    {
        var g = from m in menuList
                where ((MenuEntity)m).ParentMenuId == parentMenuId
                select (MenuEntity)m;

        foreach (MenuEntity menu in g)
        {
            var newMenu = new Menu();
            newMenu.Id = menu.Id;
            newMenu.Name = menu.Name;

            newMenu.ChildMenu = new List<Menu>();

            FillMenu(menuList, newMenu.ChildMenu, newMenu.Id);

            hList.Add(newMenu);
        }

    }

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