datatable使用groupby进行分组统计

如何在datatable中进行分组，并且计算分组后每组的数量，想了一下，可以使用LINQ来实现datatable分组。代码如下

效果

区域 库房 数量

北京---北京仓库---1

北京---上海仓库---1

上海---上海仓库---2

DataTable dt = new DataTable("cart");

DataColumn dc1 = new DataColumn("areaid", Type.GetType("System.String"));

DataColumn dc2 = new DataColumn("house", Type.GetType("System.String"));

DataColumn dc3 = new DataColumn("seq", Type.GetType("System.String"));

DataColumn dc4 = new DataColumn("remark", Type.GetType("System.String"));

dt.Columns.Add(dc1);

dt.Columns.Add(dc2);

dt.Columns.Add(dc3);

dt.Columns.Add(dc4);

DataRow dr = dt.NewRow();

dr["areaid"] = "北京";

dr["house"] = "北京仓库";

dr["seq"] = "2";

dr["remark"] = "货到付款";

dt.Rows.Add(dr);

DataRow dr1 = dt.NewRow();

dr1["areaid"] = "北京";

dr1["house"] = "上海仓库";

dr1["seq"] = "1";

dr1["remark"] = "货到付款";

dt.Rows.Add(dr1);

DataRow dr2 = dt.NewRow();

dr2["areaid"] = "上海";

dr2["house"] = "上海仓库";

dr2["seq"] = "1";

dr2["remark"] = "货到付款";

dt.Rows.Add(dr2);

DataRow dr3 = dt.NewRow();

dr3["areaid"] = "上海";

dr3["house"] = "北京仓库";

dr3["seq"] = "1";

dr3["remark"] = "货到付款";

dt.Rows.Add(dr3);

var query = from t in dt.AsEnumerable()

group t by new { t1 = t.Field<string>("areaid"), t2 = t.Field<string>("seq") } into m

select new

{

areaid = m.Key.t1,

seq = m.Key.t2,

house = m.First().Field<string>("house"),

rowcount = m.Count()

};

Console.WriteLine("区域 " + " 库房" + " 数量");

foreach (var item in query.ToList())

{

if (item.rowcount > 1)

{

Console.WriteLine(item.areaid + "---" + item.house);

}

Console.WriteLine(item.areaid + "---" + item.house + "---" + item.rowcount);

Console.WriteLine("\r\n");

}

Console.ReadKey();