表格:
**timeslot**:
----------
id_timeslot times
1 09:00
2 09:30
3 10:00
4 10:30
5 11:00
**bookslot**
id id_timeslot date b_ref
-------------------------------------------
1 2 2010-02-22 001
2 3 2010-02-22 001
3 4 2010-02-22 001
4 5 2010-02-22 001
5 2 2010-02-25 002
6 3 2010-02-27 003
7 4 2010-02-27 003
8 5 2010-02-27 003
PHP
$q = $mysqli->query("SELECT * FROM bookslot
LEFT JOIN timeslot ON bookslot.id_timeslot = timeslot.id_timeslot
WHERE bookslot.status = 1
GROUP BY bookslot.b_ref
ORDER BY bookslot.date ASC, bookslot.id_timeslot ASC LIMIT 20");
HTML 结果:
DATE TIMES
2010-02-22 10:30
2010-02-25 09:30
2010-02-27 11:00
任何人都注意到表上的结果。时间顺序不对？
我用 ASC/DESC 改变了另一种方式，仍然显示最后一个 id_timeslot 的时间？
预期结果:
DATE TIMES
2010-02-22 09:30
2010-02-25 09:30
2010-02-27 10:00
最佳答案
您的 GROUP BY bookslot.b_ref 正在对记录进行分组，因此您只能看到每种情况下的最后一次。
尝试使用
SELECT date, time, MIN(bookslot.id_timeslot)
FROM bookslot
LEFT JOIN timeslot ON bookslot.id_timeslot = timeslot.id_timeslot
WHERE bookslot.status = 1
GROUP BY bookslot.b_ref
ORDER BY bookslot.date ASC, bookslot.id_timeslot ASC LIMIT 20
关于php mysql asc/desc顺序，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/5078381/