Question

我正在尝试将多个表合并为一个，并通过将表从列转换为行来更改数据集的结构。我正在使用MySQL。

我现在已经尝试了几天来找到一个智能解决方案，而无需手动将具有唯一ID的每一行转换为具有相同ID的多行。但是，我发现自己陷入困境。

我当前的数据集：

表一：

ID    M1 amount    M2 amount    M3 amount
1234  $400 543,00  $600 000,00  $500 321,00 
4566  $500 321,00  $300 012,00  $200 345,00 
3311  $300 000,00  $450 000,00  $100 312,00

表二：

ID    M1 units  M2 units  M3 units
1234  30811 pc  46154 pc  38486 pc
4566  38486 pc  23078 pc  15411 pc
3311  23077 pc  34615 pc  7716 pc

我想要实现的是一个具有以下结构的表：

ID    M    Units    Amounts
1234  1    30811 pc  $400 543,00 
1234  2    46154 pc  $600 000,00 
1234  3    38486 pc  $500 321,00 
4566  1    38486 pc  $500 321,00 
4566  2    23078 pc  $300 012,00 
4566  3    15411 pc  $200 345,00 
3311  1    23077 pc  $300 000,00 
3311  2    34615 pc  $450 000,00 
3311  3    7716 pc   $100 312,00

我非常感谢你对这个问题的帮助。

Answer 1

以下sql脚本可以完成这项工作。使用UNION ALL，我们将Mx units和Mx amount数据转换为行，并将其保存在 临时表 中。然后我们将其加入ID和M列。

CREATE TEMPORARY TABLE tmp_t1 AS (
    SELECT *
    FROM (
        SELECT ID, `M1 amount` AS Amount, '1' AS M FROM t1
        UNION ALL
        (SELECT ID, `M2 amount` AS Amount, '2' AS M FROM t1)
        UNION ALL
        (SELECT ID, `M3 amount` AS Amount, '3' AS M FROM t1)
    ) AS x
    ORDER BY ID ASC
);

CREATE TEMPORARY TABLE tmp_t2 AS (
    SELECT *
    FROM (
        SELECT ID, `M1 units` AS Units, '1' AS M FROM t2
        UNION ALL
        (SELECT ID, `M2 units` AS Units, '2' AS M FROM t2)
        UNION ALL
        (SELECT ID, `M3 units` AS Units, '3' AS M FROM t2)
    ) AS x
    ORDER BY ID ASC
);

SELECT
    t1.ID,
    t1.M,
    t2.Units,
    t1.Amount
FROM
    tmp_t1 AS t1
INNER JOIN tmp_t2 AS t2 ON t1.ID = t2.ID AND t1.M = t2.M;

输出

+------+---+----------+-------------+
| ID   | M | Units    | Amount      |
+------+---+----------+-------------+
| 1234 | 1 | 30811 pc | $400 543,00 |
| 1234 | 2 | 46154 pc | $600 000,00 |
| 1234 | 3 | 38486 pc | $500 321,00 |
| 3311 | 1 | 23077 pc | $300 000,00 |
| 3311 | 2 | 34615 pc | $450 000,00 |
| 3311 | 3 | 7716 pc  | $100 312,00 |
| 4566 | 1 | 38486 pc | $500 321,00 |
| 4566 | 2 | 23078 pc | $300 012,00 |
| 4566 | 3 | 15411 pc | $200 345,00 |
+------+---+----------+-------------+

示例数据

DROP DATABASE IF EXISTS so_example;
CREATE DATABASE so_example;
USE so_example;

CREATE TABLE t1 (
    ID INT UNSIGNED NOT NULL PRIMARY KEY,
    `M1 amount` VARCHAR(255),
    `M2 amount` VARCHAR(255),
    `M3 amount` VARCHAR(255)
);

INSERT INTO t1 (ID, `M1 amount`, `M2 amount`, `M3 amount`) VALUES
('1234', '$400 543,00', '$600 000,00', '$500 321,00'),
('4566', '$500 321,00', '$300 012,00', '$200 345,00'),
('3311', '$300 000,00', '$450 000,00', '$100 312,00');

CREATE TABLE t2 (
    ID INT UNSIGNED NOT NULL PRIMARY KEY,
    `M1 units` VARCHAR(255),
    `M2 units` VARCHAR(255),
    `M3 units` VARCHAR(255)
);

INSERT INTO t2 (ID, `M1 units`, `M2 units`, `M3 units`) VALUES
('1234', '30811 pc', '46154 pc', '38486 pc'),
('4566', '38486 pc', '23078 pc', '15411 pc'),
('3311', '23077 pc', '34615 pc', '7716 pc');

MySQL结合表和＆amp;将具有唯一行ID的多个列转置为非唯一行

1 个答案: