打雜工程師 Ryuk 的工具簿

概述

由於手上具有大量資料，並且需要將種類與次種類的數據進行統計，故使用 Linq 的 Groupby 將二階資料進行合併計算

正文

資料可能如下：

var test = new List<model>
	{
		new model {Id = 1, group = "a", project = "a", score = 10},
		new model {Id = 2, group = "a", project = "a", score = 10},
		new model {Id = 3, group = "a", project = "b", score = 20},
		new model {Id = 4, group = "a", project = "c", score = 30},
		new model {Id = 5, group = "b", project = "a", score = 10},
		new model {Id = 6, group = "b", project = "b", score = 20},
		new model {Id = 7, group = "c", project = "a", score = 10},
	};

Table 顯示如下：

使用方法：

var data = test.GroupBy(X => new
	{
		X.group,
		X.project
	}).Select(Y => new
	{
		group = Y.Key.group,
		project = Y.Key.project,
		score = Y.Sum(Z => Z.score)
	});

GroupBy 可以直接將兩個 Column 相同的值進行 GroupBy，這是我之前不熟悉，所以不知道的

GroupBy 後將需要的資料再進行 Select 即可得到我們想要的數據

輸出結果如下：

以上我們可以看到 Group A 的兩個 Project A 分數都被合併

 

完整程式碼：

void Main()
{
	var test = new List<model>
	{
		new model {Id = 1, group = "a", project = "a", score = 10},
		new model {Id = 2, group = "a", project = "a", score = 10},
		new model {Id = 3, group = "a", project = "b", score = 20},
		new model {Id = 4, group = "a", project = "c", score = 30},
		new model {Id = 5, group = "b", project = "a", score = 10},
		new model {Id = 6, group = "b", project = "b", score = 20},
		new model {Id = 7, group = "c", project = "a", score = 10},
	};
	
	var data = test.GroupBy(X => new
	{
		X.group,
		X.project
	}).Select(Y => new
	{
		group = Y.Key.group,
		project = Y.Key.project,
		score = Y.Sum(Z => Z.score)
	});
}

public class model
{
	public int Id { get; set; }
	public string group { get; set; }
	public string project { get; set; }
	public int score { get; set; }
}

 

分級： 入門是認識， 基本是運用， 進階是混合結合

範本是已可下載或可使用的範例， 至於教程當然是學習的結晶