用SQL语句实现行列转换很容易,但也有时候需要在程序中实现,找了好久,发现一篇文章写的挺不错的
用LINQ实现的行列转换,借鉴了他的办法,修改了下,达到了想要的效果
原始表:
想要达到的效果:
1 private void Form1_Load(object sender, EventArgs e) 2 { 3 //创建表,添加数据作为数据源 4 DataTable dtSource = new DataTable(); 5 dtSource.Columns.Add(new DataColumn("Name",typeof(string)));//姓名 6 dtSource.Columns.Add(new DataColumn("DateTime", typeof(string)));//日期 7 dtSource.Columns.Add(new DataColumn("WorkType", typeof(string)));//上班类型 8 9 dtSource.Rows.Add("张三","周一","早班");10 dtSource.Rows.Add("张三", "周二", "晚班");11 dtSource.Rows.Add("张三", "周三", "早班");12 dtSource.Rows.Add("小李", "周二", "早班");13 dtSource.Rows.Add("小李", "周四", "早班");14 dtSource.Rows.Add("小李", "周五", "早班");15 dtSource.Rows.Add("小王", "周一", "晚班");16 dtSource.Rows.Add("小王", "周三", "晚班");17 dtSource.Rows.Add("小王", "周五", "晚班");18 19 gc.DataSource=GetTable(dtSource); //输出转换后的表(这用的是DEV控件的GridView)20 }21 22 ///23 /// 实现行列转换24 /// 25 private DataTable GetTable(DataTable dtSource)26 {27 //创建转换后的表,固定列28 DataTable dt = new DataTable();29 dt.Columns.Add("NAME", typeof(string)); //名称30 dt.Columns.Add("WEEK1", typeof(string)); //周一31 dt.Columns.Add("WEEK2", typeof(string)); //周二32 dt.Columns.Add("WEEK3", typeof(string)); //周三33 dt.Columns.Add("WEEK4", typeof(string)); //周四34 dt.Columns.Add("WEEK5", typeof(string)); //周五35 string[] times = new string[] { "周一", "周二", "周三", "周四", "周五" };//存放日期作为筛选条件36 37 //x[0]为NAME,按NAME 分组38 var data = from x in dtSource.Rows.Cast()39 group x by x[0] into g40 select new { Key = g.Key.ToString(), Items = g };41 data.ToList().ForEach(x =>42 {43 string[] array = new string[dt.Columns.Count];44 array[0] = x.Key;//NAME45 int m = 0;46 for (int i = 1; i < dt.Columns.Count; i++)47 {48 array[i] = (from y in x.Items49 where y[1].ToString() == times[m] //y[1]为日期,上面的times为筛选条件50 select y[2].ToString()).SingleOrDefault();//筛选出来的上班类型51 m++;52 };53 dt.Rows.Add(array);54 }55 );56 return dt;57 }
输出的效果图: