MySQL：枚举计数

Question

我有两个 table，table1 和 table2。

table1 table.

示例

^ invoice ^ valid ^ 
| 10       | yes   | 
| 11       | yes   | 
| 12       | no    |

示例 table2 table

^ invoice ^ detail ^ 
| 10       | A      | 
| 10       | C      | 
| 10       | F      | 
| 11       | A      | 
| 11       | F      |
| 10       | E      | 
| 12       | A      |

想要 select 来自 table 2 的所有行：

在 table 1

并枚举：

每张发票的详细信息
发票

这里是想要的结果

^ invoice ^ detail ^ ordination ^ ordinationb      ^ 
| 10       | A      |     1       |       1         | 
| 10       | C      |     2       |       1         |  
| 10       | F      |     3       |       1         |  
| 11       | A      |     1       |       2         |  
| 11       | F      |     2       |       2         | 
| 10       | E      |     4       |       1         |

这句话应该适用于 phpMyAdmin 4.8.4

Answer 1

这是 MySQL 8+ 的实现方式：

SELECT
    t2.Invoice,
    t2.`lines`,
    ROW_NUMBER() OVER (PARTITION BY t2.Invoice ORDER BY t2.`lines`) line_order,
    DENSE_RANK() OVER (ORDER BY t2.Invoice) ordination
FROM table2 t2
WHERE EXISTS (SELECT 1 FROM table1 t1 WHERE t1.Invoice = t2.Invoice AND t1.valid = 'yes');

Demo

如果您使用的 MySQL 版本早于 8，那么您可能不得不求助于使用会话变量。这可能会导致难看的查询。如果您长期需要这样的查询，那么我建议升级到 MySQL 8+。

编辑：

我突然意识到我们可以使用相关子查询来模拟您的 ROW_NUMBER 和 DENSE_RANK 需求。这是在 MySQL 5.7 或更早版本中执行此查询的一种方法：

SELECT
    t2.Invoice,
    t2.detail,
    (SELECT COUNT(*) FROM table2 t
    WHERE t.Invoice = t2.Invoice AND t.detail <= t2.detail) ordination,
    t.dr AS ordinationb
FROM table2 t2
INNER JOIN
(
    SELECT DISTINCT
        t2.Invoice,
        (SELECT COUNT(*)
         FROM (SELECT DISTINCT Invoice FROM table2) t
         WHERE t.Invoice <= t2.Invoice) dr
    FROM table2 t2
) t
    ON t.Invoice = t2.Invoice
WHERE EXISTS (SELECT 1 FROM table1 t1 WHERE t1.Invoice = t2.Invoice AND t1.valid = 'yes')
ORDER BY
    t2.Invoice,
    t2.detail;

MySQL：枚举计数

MySQL: Enumerate and count

mysql

enumerate

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Demo

Demo