【情况如下】
在表1中 记录着
自行车编号 租户商家
<code>1 a 2 a 3 b 4 c </code>
[这里的意思是,不同的商家。拥有的自行车,商家拥有自行车表]
表2
自行车编号 租出时间 租出金额
<code>1 2 4 1 3 5 1 6 10 2 3 5 3 4 7 </code>
[这里 意味着。不同的商家 对自己的自行车 租出时间不同设置的价格,自行车价格表]
表3
自行车编号 租出时间 租的人
<code>1 2 用户1 1 3 用户2 2 4 用户3 3 2 用户4 4 1 用户5 [这里指,用户,在今天使用的自行车和租的时间,租车记录] </code>
【那么问题来了】
我现在想知道
1、商家今天租车,同1车,租车总次数
最后要拿到
自行车编号 租出2小时几次? 租出3小时多少次?租出4小时多少次?
我有2种方法。第一种是用 程序 先查出所有车的租出记录。然后在用程序来统计分别租出去那种时间,和多少次。
请问这种类型的数据统计。PHP一般是怎么来达到既能考虑到效率。又能很简洁!
回复内容:
【情况如下】
在表1中 记录着
自行车编号 租户商家
<code>1 a 2 a 3 b 4 c </code>
[这里的意思是,不同的商家。拥有的自行车,商家拥有自行车表]
表2
自行车编号 租出时间 租出金额
<code>1 2 4 1 3 5 1 6 10 2 3 5 3 4 7 </code>
[这里 意味着。不同的商家 对自己的自行车 租出时间不同设置的价格,自行车价格表]
表3
自行车编号 租出时间 租的人
<code>1 2 用户1 1 3 用户2 2 4 用户3 3 2 用户4 4 1 用户5 [这里指,用户,在今天使用的自行车和租的时间,租车记录] </code>
【那么问题来了】
我现在想知道
1、商家今天租车,同1车,租车总次数
最后要拿到
自行车编号 租出2小时几次? 租出3小时多少次?租出4小时多少次?
我有2种方法。第一种是用 程序 先查出所有车的租出记录。然后在用程序来统计分别租出去那种时间,和多少次。
请问这种类型的数据统计。PHP一般是怎么来达到既能考虑到效率。又能很简洁!
这个直接就可以用sql语句来解决,用左连接可以查出任何你想要的数据,如果用php处理的话,一次性把所有的数据都取出来,然后再处理也是可以的,千万不要循环中再去查询数据库。

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