使用列中的不同值作为代码中的列名创建表[关闭]答案

【问题标题】：create a table using distinct values from a column as the column names in a code [closed]使用列中的不同值作为代码中的列名创建表[关闭]
【发布时间】：2017-01-02 11:54:41
【问题描述】：

我有一个如下图所示的表格，其中包含一些不同的值。我想为 R 列中的每个不同值创建一个新表，列名将以 S 开头。在此先感谢您的帮助。（在 sql server 或 c# 或 vb.net 中）

我的桌子：

姓名家庭 R C D --------------------- N1 F1 S1 1 安 N2 F2 S2 2 安 N3 F3 S1 1 乙 N4 F4 S2 2 乙 N5 F5 S3 3 一个

新表：

S1 S2 S3 ....... --------------------------------- 一个 N1 N2 N5 ...... F1 F2 F5 ....... ---------------------------------- B N3 N4 F3 F4

【问题讨论】：

欢迎来到stackoverflow。请阅读How to Ask
你能指定一个阻止你创建所需表的问题吗？

标签： c# sql-server vb.net

【解决方案1】：

尝试像这样创建一个数据透视表：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {

            DataTable dt = new DataTable();

            dt.Columns.Add("Name", typeof(string));
            dt.Columns.Add("Family", typeof(string));
            dt.Columns.Add("R", typeof(string));
            dt.Columns.Add("C", typeof(int));
            dt.Columns.Add("D", typeof(string));

            dt.Rows.Add(new object[] {"N1","F1","S1", 1, "A"});
            dt.Rows.Add(new object[] {"N2","F2","S2", 2, "A"});
            dt.Rows.Add(new object[] {"N3","F3","S1", 1, "B"});
            dt.Rows.Add(new object[] {"N4","F4","S2", 2, "B"});
            dt.Rows.Add(new object[] {"N5","F5","S3", 3, "A"});

            string[] uniqueRs = dt.AsEnumerable().Select(x => x.Field<string>("R")).Distinct().OrderBy(x => x).ToArray();

            DataTable pivot = new DataTable();
            pivot.Columns.Add("D", typeof(string));
            foreach (string uniqueR in uniqueRs)
            {
                pivot.Columns.Add(uniqueR, typeof(string));
            }

            var groups = dt.AsEnumerable().GroupBy(x => x.Field<string>("D"));

            foreach (var group in groups)
            {
                List<string> names = group.OrderBy(x => x.Field<int>("C")).Select(x => x.Field<string>("Name")).ToList();
                names.Insert(0, group.Key);
                pivot.Rows.Add(names.ToArray());

                List<string> families = group.OrderBy(x => x.Field<int>("C")).Select(x => x.Field<string>("Family")).ToList();
                families.Insert(0, group.Key);
                pivot.Rows.Add(families.ToArray());
            }

        }
    }
}

【讨论】：

【解决方案2】：

但是你想要这个要求的确切目的是什么

样本数据：

DECLARE @Table1  TABLE 
    (Name varchar(2), Family varchar(2), R varchar(2), C int, D varchar(1))
;

INSERT INTO @Table1
    (Name, Family, R, C, D)
VALUES
    ('N1', 'F1', 'S1', 1, 'A'),
    ('N2', 'F2', 'S2', 2, 'A'),
    ('N3', 'F3', 'S1', 1, 'B'),
    ('N4', 'F4', 'S2', 2, 'B'),
    ('N5', 'F5', 'S3', 3, 'A')
;

脚本

;with CTE as (
SELECT D,
[S1],
[S2],
[S3] 
        FROM (
select Name,
       Family, 
       R, 
       C, 
       D 
            FROM @Table1)t
                PIVOT (MAX(Name) For R in ([S1],[S2],[S3])
)pvt 
                GROUP BY  D,[S1],[S2],[S3] )
,
 CTE2 AS (

 SELECT D,
       [S1],
       [S2],
       [S3] 
         FROM (
select Name, 
       Family, 
       R, 
       C, 
       D FROM @Table1)t
            PIVOT (MAX(Family) For r in ([S1],[S2],[S3])
)pvt 
GROUP BY  D,[S1],[S2],[S3])

Select 
    CASE WHEN RN = 1 THEN D ELSE NULL END NAME ,S1,S2,S3 FROM (
Select *,
        Row_number()OVER(PARTITION BY D ORDER BY (SELECT NULL))RN from (
            SELECT  D,
            (SELECT S1 FROM cte where S1 IS NOT NULL AND C.D = D)S1,
            (SELECT S2 FROM cte where S2 IS NOT NULL AND C.D = D)S2,
            (SELECT S3 FROM cte where S3 IS NOT NULL AND C.D = D)S3  FROM  CTE C
            UNION 
            SELECT  D,
            (SELECT S1 FROM CTE2 where S1 IS NOT NULL AND C.D = D)S1,
            (SELECT S2 FROM CTE2 where S2 IS NOT NULL AND C.D = D)S2,
            (SELECT S3 FROM CTE2 where S3 IS NOT NULL AND C.D = D)S2  FROM cte2 C)T)TT

【讨论】：