我们有3张桌子:
捐赠:
+--------+------+
| do_id | name |
+--------+------+
| 1 | A |
| 2 | B |
| 3 | A |
| 4 | D |
| 5 | B |
| 6 | B |
| 7 | A |
| 8 | B |
+--------+----- +
目的:
+-------+-------+--------+
| pu_id | do_id | purpose|
+-------+-------+--------+
| 1 | 2 | abc |
| 2 | 2 | def |
| 3 | 2 | gih |
| 4 | 3 | jkl |
+-------+-------+--------+
费用:
+-------+-------+---------+
| ex_id | do_id | expense |
+-------+-------+---------+
| 1 | 2 | abc |
| 2 | 2 | def |
| 3 | 2 | gih |
| 4 | 3 | jkl |
+-------+-------+---------+
现在,我要查询以获取捐赠方 B 的所有捐赠,并加入目的表以获取与每个 donation_id 相关的所有目的加入费用表以获取与 donation_id 相关的所有费用,并将所有这些费用独立地放入每个循环中
Row number 0
donation_id = 1
array(purposes)
array(expenses)
Row number 1
donation_id = 2
array(purposes)
array(expenses)
Row number 2
donation_id = 3
array(purposes)
array(expenses)
Row number 3
donation_id = 4
array(purposes)
array(expenses)
这是我的尝试:
SELECT *, (
SELECT *
FROM `donation_purposes`
WHERE `donation_purposes`.`dopu_donation_id` = 4
) AS `purposes`
FROM `donations`
WHERE `donation_id` = '4'
预先感谢
答案 0 :(得分:0)
您应该能够使用MySQL aggregate function JSON_ARRAYAGG()
使用汇总查询来解决这个问题,例如:
SELECT
d.do_id,
JSON_ARRAYAGG(p.purpose) purposes,
JSON_ARRAYAGG(e.expense) expenses
FROM donations d
INNER JOIN purposes p ON p.do_id = d.do_id
INNER JOIN expense e ON e.do_id = d.do_id
GROUP BY d.do_id
我要避免在数组中重复值,并且由于JSON_ARRAYAGG()
(很难)不支持DISTINCT
选项,因此可以将聚合移至子查询,例如:
SELECT
d.do_id,
p.agg purpose,
e.agg expenses
FROM donations d
INNER JOIN (
SELECT do_id, JSON_ARRAYAGG(purpose) agg FROM purposes GROUP BY do_id
) p ON p.do_id = d.do_id
INNER JOIN (
SELECT do_id, JSON_ARRAYAGG(expense) agg FROM expense GROUP BY do_id
) e ON e.do_id = d.do_id
此 demo on DB Fiddle 返回:
| do_id | purpose | expenses |
| ----- | --------------------- | --------------------- |
| 2 | ["abc", "def", "gih"] | ["abc", "def", "gih"] |
| 3 | ["jkl"] | ["jkl"] |
答案 1 :(得分:0)
第一个选择查询目的
SELECT purposes.* FROM purposes
LEFT JOIN donations
ON purposes.do_id = donations.do_id
WHERE donations.do_id = '2' //This depends on the id of the donation
ORDER BY purposes.do_id ASC
第二次选择查询费用
SELECT expense.* FROM expense
LEFT JOIN donations
ON expense.do_id = donations.do_id
WHERE donations.do_id = '2' //This depends on the id of the donation
ORDER BY expense.ex_id ASC
生成的所有查询均来自您提供的表结构,但是您的问题很模糊!