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C#,LInq,实体框架4:使用LInq将表拆分为二维数组

linq-to-entities linq c#

Zachary Scott · 技术社区 · 14 年前

我有这样一个实体:

public class Category
{
    public int classid {get;set;}
    public int itemid {get;set;}
    public string label {get;set;}
}

所以一个列表产生这个JSON(三种大小和三种颜色

[{"classid":1,"itemid":1,"label":"Small"},
 {"classid":1,"itemid":2,"label":"Medium"},
 {"classid":1,"itemid":3,"label":"Large"},

 {"classid":2,"itemid":1,"label":"Blue"},
 {"classid":2,"itemid":2,"label":"Green"},
 {"classid":2,"itemid":3,"label":"Red"},

 {"classid":3,"itemid":1,"label":"Tee"},
 {"classid":3,"itemid":2,"label":"Golf"},
 {"classid":3,"itemid":3,"label":"Dress"}]

myarray[][].label :

[[{"itemid":1,"label":"Small"},
  {"itemid":2,"label":"Medium"},
  {"itemid":3,"label":"Large"}],

 [{"itemid":1,"label":"Blue"},
  {"itemid":2,"label":"Green"},
  {"itemid":3,"label":"Red"}],

 [{"itemid":1,"label":"Tee"},
  {"itemid":2,"label":"Golf"},
  {"itemid":3,"label":"Dress"}]]

这是我的Linq查询的中间部分。

如何构造Linq查询以从Linq中的一维数组组装二维数组?

编辑:现有查询:

 ...
 CATS = (from myP in myProduct.ProductCategories
        select new ProductCategory
        {
            classid = myP.classid,
            itemid = myP.itemid,
            label = myP.label
        }),
 ...

编辑:越来越近:

CATS = (from myP in myProduct.ProductCategories
        group myP by myP.classid into groups
        select new resultClass
        {  classid = groups.Key,
              opts = groups.Select(x => 
              new ProductOption 
              { itemid = x.itemid,
                label = x.label}) }),

1 回复 | 直到 14 年前

John Fisher 14 年前

我还没有测试过,但这是一个熟悉的领域,应该有用:

IEnumerable<Category> items = ...;
var groups = items.GroupBy(x => x.classid);
var arrays = groups.Select(x => 
    x.Select(y => new { itemid = y.itemid, label = y.label }).ToArray()
).ToArray();

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