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这是我的表“资产”

+----+----------------------------+-------+-----------+
| id | model                      | grade | warehouse |
+----+----------------------------+-------+-----------+
|  1 | Optiplex 9030 AIO i5       |     2 |         2 |
|  2 | Optiplex 9030 AIO i3 Touch |     2 |         2 |
|  3 | Optiplex 9030 AIO i7       |     2 |         1 |
|  4 | Optiplex 9030 AIO i5 Touch |     1 |         1 |
|  5 | Optiplex 9030 AIO i7       |     1 |         1 |
|  6 | Optiplex 9030 AIO i7       |     2 |         1 |
|  7 | Optiplex 9030 AIO i7       |     1 |         2 |
|  8 | Optiplex 9030 AIO i5 Touch |     2 |         2 |
|  9 | Optiplex 9030 AIO i5       |     1 |         1 |
| 10 | Optiplex 9030 AIO i5       |     2 |         2 |
+----+----------------------------+-------+-----------+

我想做的是

SELECT id, model, grade, @ids := GROUP_CONCAT(id) AS ids, 
(SELECT COUNT(*) FROM assets WHERE id IN (@ids) AND warehouse = 1 ) AS w_1_count,
(SELECT COUNT(*) FROM assets WHERE id IN (@ids) AND warehouse = 2 ) AS w_2_count
FROM `assets` GROUP BY model, grade

它给我这样的结果

+----+----------------------------+-------+------+-----------+-----------+
| id | model                      | grade | ids  | w_1_count | w_2_count |
+----+----------------------------+-------+------+-----------+-----------+
|  2 | Optiplex 9030 AIO i3 Touch |     2 | 2    |         1 |         0 |
|  9 | Optiplex 9030 AIO i5       |     1 | 9    |         0 |         1 |
|  1 | Optiplex 9030 AIO i5       |     2 | 1,10 |         1 |         0 |
|  4 | Optiplex 9030 AIO i5 Touch |     1 | 4    |         0 |         1 |
|  8 | Optiplex 9030 AIO i5 Touch |     2 | 8    |         1 |         0 |
|  5 | Optiplex 9030 AIO i7       |     1 | 5,7  |         0 |         1 |
|  3 | Optiplex 9030 AIO i7       |     2 | 3,6  |         1 |         0 |
+----+----------------------------+-------+------+-----------+-----------+

预期的结果是：我想得到哪个？但没有运气

+----+----------------------------+-------+------+-----------+-----------+
| id | model                      | grade | ids  | w_1_count | w_2_count |
+----+----------------------------+-------+------+-----------+-----------+
|  2 | Optiplex 9030 AIO i3 Touch |     2 | 2    |         0 |         1 |
|  9 | Optiplex 9030 AIO i5       |     1 | 9    |         1 |         0 |
|  1 | Optiplex 9030 AIO i5       |     2 | 1,10 |         0 |         2 |
|  4 | Optiplex 9030 AIO i5 Touch |     1 | 4    |         1 |         0 |
|  8 | Optiplex 9030 AIO i5 Touch |     2 | 8    |         0 |         1 |
|  5 | Optiplex 9030 AIO i7       |     1 | 5,7  |         1 |         1 |
|  3 | Optiplex 9030 AIO i7       |     2 | 3,6  |         2 |         0 |
+----+----------------------------+-------+------+-----------+-----------+

当我选择 @ids 变量进行显示时，它给了我奇怪的结果集

SELECT id, model, grade, @ids := GROUP_CONCAT(id) AS ids, @ids, 
(SELECT COUNT(*) FROM assets WHERE id IN (@ids) AND warehouse = 1 ) AS w_1_count,
(SELECT COUNT(*) FROM assets WHERE id IN (@ids) AND warehouse = 2 ) AS w_2_count
FROM `assets` GROUP BY model, grade

+----+----------------------------+-------+------+------+-----------+-----------+
| id | model                      | grade | ids  | @ids | w_1_count | w_2_count |
+----+----------------------------+-------+------+------+-----------+-----------+
|  2 | Optiplex 9030 AIO i3 Touch |     2 | 2    | 3,6  |         1 |         0 |
|  9 | Optiplex 9030 AIO i5       |     1 | 9    | 2    |         0 |         1 |
|  1 | Optiplex 9030 AIO i5       |     2 | 1,10 | 9    |         1 |         0 |
|  4 | Optiplex 9030 AIO i5 Touch |     1 | 4    | 1,10 |         0 |         1 |
|  8 | Optiplex 9030 AIO i5 Touch |     2 | 8    | 4    |         1 |         0 |
|  5 | Optiplex 9030 AIO i7       |     1 | 5,7  | 8    |         0 |         1 |
|  3 | Optiplex 9030 AIO i7       |     2 | 3,6  | 5,7  |         1 |         0 |
+----+----------------------------+-------+------+------+-----------+-----------+

问题：

1.) 如何实现与@ids 和另一个条件绑定的预期结果集？

2.) 为什么@ids 列显示下一行的错误值，它应该与group_concat ids 相同？我不知道我错在哪里

在这里，我附上了一个 SQL fiddle 以获得快速帮助

http://sqlfiddle.com/#!9/9e3e5d/1/0

4

1 回答 1

1

我想你只想要条件聚合。下面的解决方案加入了一个子查询，该子查询按模型和等级聚合，得出id每个组的最低值、ID 的 CSV 列表以及两个条件仓库计数。

SELECT
    a2.min_id AS id,
    a1.model,
    a1.grade,
    a2.ids,
    a2.w_1_count,
    a2.w_2_count
FROM assets a1
INNER JOIN
(
    SELECT
        model,
        grade,
        MIN(id) AS min_id,
        GROUP_CONCAT(id) AS ids,
        SUM(warehouse = 1) AS w_1_count,
        SUM(warehouse = 2) AS w_2_count
    FROM assets
    GROUP BY model, grade
) a2
    ON a1.model = a2.model AND
       a1.grade = a2.grade AND
       a1.id = a2.min_id;

这是使用上述查询的更新演示的链接：

演示

于 2020-01-20T13:50:14.680 回答