mysql - SQL:从复杂的选择中更新

Question

在电话系统场景中，我有 2 个表。

• table1 由以下内容组成:customer_id、call_duration、calldate、skip_billing。
• table2 由以下部分组成:customer_id、bonus_seconds。

表1存储所有客户的所有调用，表2存储bonus_seconds，它表示定义的客户允许的免费通话时间(即:对于客户1，前40累计秒是免费的)。

我必须根据下面解释的条件编写一个查询来更新 table1:在表2中免费定义的调用中设置skip_billing。

因此，我首先需要按 customer_id 进行分组，然后迭代调用，在 call_duration 上增加累积变量(cumsec)并相应地设置skip_billing。

表1示例是:

|sqlid |customer_id |billsec | skipbill|
|0     |1           |12      | 1       |<--need to set 1 due to cume=12 for customer_id=1
|1     |1           |10      | 1       |<--need to set 1 due to cume=22 for customer_id=1
|2     |1           |15      | 1       |<--need to set 1 due to cume=37 for customer_id=1
|3     |1           |8       | 0       |<--nop(no operation) due to cume=45
|4     |2           |12      | 1       |<--need to set 1 due to cume=12 for customer_id=2
|5     |3           |12      | 1       |<--need to set 1 due to cume=12 for customer_id=3
|6     |2           |12      | 0       |<--nop due to cume=24 for customer_id=2
|7     |1           |12      | 0       |<--nop due to cume=49 for customer_id=1
|8     |3           |15      | 0       |<--nop due to cumsec=27 for customer_id=3

|customer_id |bonus_seconds|
|1           |40           |
|2           |20           |
|3           |15           |

我尝试使用这样的查询(感谢 Gordon Linoff)，它返回正确的行集:

    SELECT t.cume, t.calldate, t.customer_id FROM (SELECT t.*, (@cume := @cume + billsec) AS cume FROM table1 t CROSS JOIN (SELECT @cume := 0) vars ORDER BY calldate) t, table2 sct WHERE t.cume <= sct.bonus_seconds AND t.customer_id=sct.customer_id ;

但是当我尝试像下面的命令一样使用 UPDATE 时，它不起作用，因为不匹配任何内容。

    UPDATE table1 SET skipbill=1 WHERE sqlid=(SELECT t.sqlid FROM (SELECT t.*, (@cume := @cume + billsec) AS cume FROM table1 t CROSS JOIN (SELECT @cume := 0) vars ORDER BY calldate) t, table2 sct WHERE t.cume <= sct.bonus_seconds AND t.customer_id=sct.customer_id ) ;

如何使用该查询或更好的查询来编写更新任务？

提前谢谢

Answer 1

UPDATE table1 
SET skipbill = 1 
WHERE sqlid IN (
    SELECT DISTINCT t.sqlid 
    FROM (
        SELECT t.*, (@cume := @cume + billsec) AS cume 
        FROM table1 t 
        CROSS JOIN (SELECT @cume := 0) vars 
        ORDER BY calldate
    ) t, table2 sct 
    WHERE t.cume <= sct.bonus_seconds 
          AND t.customer_id = sct.customer_id
);