Question

我有两张桌子：

tickets

ticket_id, int(11), NO, PRI, , auto_increment
order_num, varchar(45), NO, , , 
user_id, int(11), YES, , , 
event_id, int(11), YES, , , 
number_of_tickets, varchar(4), YES, , , 
order_placed, timestamp, NO, , CURRENT_TIMESTAMP, 
payment_recd, enum('Yes','No'), YES, , No, 
payment_time, timestamp, YES, , , 

events

event_id, int(11), NO, PRI, , auto_increment
venue_id, int(11), YES, , , 
event_date, date, YES, , , 
event_time, time, YES, , , 
event_price, decimal(4,2), YES, , , 
event_capacity, int(11), YES, , , 
dateadded, timestamp, NO, , CURRENT_TIMESTAMP,

我需要列出用户购买的门票并按活动日期排序，但我正在尝试的以下内容未正确排序

select tickets.order_num as ordnum, tickets.event_id as tickid, tickets.number_of_tickets as numtix 
   from tickets, events
where  ((tickets.user_id = '1') and (tickets.payment_recd = 'Yes'))
  group by tickets.order_num 
order by events.event_date asc

有什么想法吗？

Answer 1

您没有加入表格，因此会列出两个表格中的所有行，请尝试：

select tickets.order_num as ordnum, tickets.event_id as tickid, tickets.number_of_tickets as numtix 
from tickets
inner join events on tickets.event_id = events.event_id
where ((tickets.user_id = '1') && (tickets.payment_recd = 'Yes'))
group by tickets.order_num order by events.event_date asc

Answer 2

首先，我建议您使用JOIN，因为您的方法太慢，JOIN最快，更安全，实际上是您能够使用的最有效的解决方案，并且数据库正确写入

SELECT t.order_num, t.event_id, t.number_of_tickets 
FROM tickets t
INNER JOIN events e ON (t.event_id = e.event_id)
WHERE ((t.user_id = '1') && (t.payment_recd = 'Yes'))
GROUP BY t.order_num
ORDER BY e.event_date ASC

Answer 3

尝试：

select tickets.order_num as ordnum, tickets.event_id as tickid, tickets.number_of_tickets as numtix 
   from events
  inner join tickets on events.id = ticket.event_id
where  ((tickets.user_id = '1') and (tickets.payment_recd = 'Yes'))
  group by tickets.order_num 
order by events.event_date asc

您没有显示events和tickets表格之间的关系，获取笛卡尔积。

Answer 4

你的where子句中需要一个'AND tickets.event_id = events.event_id'。

您尚未指定如何加入这两个表，因此目前您正在进行完全加入。

Answer 5

尝试使用它

 select tickets.order_num as ordnum, tickets.event_id as tickid,
 tickets.number_of_tickets as numtix from tickets inner join events on
    tickets.event_id=events.event_id where
 ((tickets.user_id = 1) && (tickets.payment_recd = 'Yes'))
 group by tickets.order_num order by events.event_date asc

并且请考虑ticket.user_id是一个整数，你不能把它表现为带有''的字符串...... 它必须像尝试使用ticket.user_id = 1

MySQL加入，订单不正确

5 个答案: