我已经为此工作了大约两天，似乎无法弄清楚，因此我希望获得一些帮助。
我有两个表：
mysql> select id, date, volume, symbol_id from control_quotedaily limit 5;
+-------+---- -------+----------+-----------+
| id | date | volume | symbol_id |
+-------+------------+----------+-----------+
| 13263 | 2017-11-02 | 7800191 | AXISBANK |
| 13264 | 2017-11-02 | 9303981 | SBIN |
| 13265 | 2017-11-02 | 8013536 | HDFCBANK |
| 13266 | 2017-11-03 | 9642624 | AXISBANK |
| 13267 | 2017-11-04 | 19642327 | AXISBANK |
+-------+------------+----------+-----------+
5 rows in set (0.00 sec)
14 rows in set (0.01 sec)
mysql> select * from control_oidaily
+-----------+------------+-------------+--------------+
| symbol_id | date | expiry_date | val_in_lakhs |
+-----------+------------+-------------+--------------+
| AXISBANK | 2017-11-02 | 2017-11-30 | 166881.8 |
| AXISBANK | 2017-11-02 | 2017-12-28 | 2676.84 |
| AXISBANK | 2017-11-02 | 2018-01-25 | 97.13 |
| HDFCBANK | 2017-11-02 | 2017-11-30 | 76351.11 |
| HDFCBANK | 2017-11-02 | 2017-12-28 | 1509.48 |
| HDFCBANK | 2017-11-02 | 2018-01-25 | 0 |
| SBIN | 2017-11-02 | 2017-11-30 | 88654.3 |
| SBIN | 2017-11-02 | 2017-12-28 | 1060.51 |
| SBIN | 2017-11-02 | 2018-01-25 | 0 |
| AXISBANK | 2017-11-03 | 2017-11-30 | 87640.06 |
+-----------+------------+-------------+--------------+
因此，对于control_quotedaily表中的每个报价，这就是我想要的：
control_oidaily表中与该报价最接近的expiry_date
我想要该有效日期的val_in_lakhs。
例如：对于日期2017-11-02，最接近的到期日期是2017-11-30，我希望返回val_in_lakhs（76351.11）。
这是我正在尝试的：
select o.date, o.expiry_date as expiry_date, o.symbol_id, q.date, q.symbol_id, o.val_in_lakhs, q.tottrdval, q.volume, q.symbol_id
FROM control_oidaily o
JOIN ( select o.date, MIN(expiry_date) as expiry_date, symbol_id
FROM control_oidaily o
GROUP by o.date,o.symbol_id
ORDER BY o.date asc) as ed
ON ed.date = o.date
AND ed.symbol_id = o.symbol_id
AND ed.expiry_date = o.expiry_date
JOIN control_quotedaily q
ON q.date = ed.date
AND q.symbol_id = ed.symbol_id
这是我期望的输出：
+-------+------------+----------+-----------+--------------+--------------+
| id | date | volume | symbol_id | expiry_date | val_in_lakhs |
+-------+------------+----------+-----------+--------------+--------------+
| 13263 | 2017-11-02 | 7800191 | AXISBANK | 2017-11-30 | 166881.8 |
| 13264 | 2017-11-02 | 9303981 | SBIN | 2017-11-30 | 88654.3 |
| 13265 | 2017-11-02 | 8013536 | HDFCBANK | 2017-11-30 | 76351.11 |
| 13266 | 2017-11-03 | 9642624 | AXISBANK | 2017-11-30 | 87640.06 |
+-------+------------+----------+-----------+--------------+--------------+
最佳答案
在Derived Table中，从closest_expiry_date表中获取expiry_date（最小值symbol_id），将date和control_oidaily分组。
将其与control_quotedaily和symbol_id上的date表连接起来，以获取control_quotedaily表中每一行的closet_expiry_date值。
现在，再次使用相同的派生表与control_oidaily表联接，在date，expiry_date（具有最接近的到期日期）和symbol_id上匹配以得到val_in_lakhs。
您可能需要以下查询：
SELECT q.id,
q.`date`,
q.volume,
q.symbol_id,
o1.expiry_date,
o1.val_in_lakhs
FROM control_quotedaily AS q
JOIN (SELECT o2.`date`,
o2.symbol_id
MIN(o2.expiry_date) as closest_expiry_date
FROM control_oidaily AS o2
GROUP by o2.`date`, o2.symbol_id
) AS dt
ON dt.`date` = q.`date`
AND dt.symbol_id = q.symbol_id
JOIN control_oidaily AS o1
ON dt.`date` = o1.`date`
AND dt.symbol_id = o1.symbol_id
AND dt.closest_expiry_date = o1.expiry_date
关于mysql - 连接两个表不能按预期工作，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/52912567/