MySql换行到列和列到行 [英] MySql Transpose Row into Column and Column into Row

问题描述

我在将行移至列和将列移至行时遇到问题. 如果它只是将行转置为列或将列转置为行，则可以这样做.

i have problem with transposing row to column and column to row. I can do that if it just transpose row to column or column to row.

这是我的数据表

UNIT|JAN|FEB|MAR|APR|MEI|JUN
CS-1|100|200|300|400|500|600
CS-2|111|222|333|444|555|666
CS-3|331|123|423|923|918|123

我想得到以下输出

MONTH|CS-1|CS-2|CS-3
JAN  |100 |111 |331
FEB  |200 |222 |123
MAR  |300 |333 |423

等.

有人知道该怎么做吗?非常感谢！

Anybody know how to do this? Thanks very much!

推荐答案

您可以这样做

SELECT month,
       MAX(CASE WHEN unit = 'CS-1' THEN value END) `CS-1`,
       MAX(CASE WHEN unit = 'CS-2' THEN value END) `CS-2`,
       MAX(CASE WHEN unit = 'CS-3' THEN value END) `CS-3`
  FROM
(
  SELECT unit, month,
         CASE month 
            WHEN 'JAN' THEN jan
            WHEN 'FEB' THEN feb
            WHEN 'MAR' THEN mar
            WHEN 'APR' THEN apr
            WHEN 'MAY' THEN may
            WHEN 'JUN' THEN jun
         END value
    FROM table1 t CROSS JOIN
  (
    SELECT 'JAN' month UNION ALL
    SELECT 'FEB' UNION ALL
    SELECT 'MAR' UNION ALL
    SELECT 'APR' UNION ALL
    SELECT 'MAY' UNION ALL
    SELECT 'JUN'
  ) c
) q
 GROUP BY month
 ORDER BY FIELD(month, 'JAN', 'FEB', 'MAR', 'APR', 'MAY', 'JUN')

输出:

| MONTH | CS-1 | CS-2 | CS-3 |
|-------|------|------|------|
|   JAN |  100 |  111 |  331 |
|   FEB |  200 |  222 |  123 |
|   MAR |  300 |  333 |  423 |
|   APR |  400 |  444 |  923 |
|   MAY |  500 |  555 |  918 |
|   JUN |  600 |  666 |  123 |

这里是 SQLFiddle 演示

Here is SQLFiddle demo

这篇关于MySql换行到列和列到行的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！