如何在结果窗格列的每个“最小”值中添加“更大”过滤器

Question

I have the following syntax:

SELECT t1.cardid, t1.Name, t2.record
FROM t2 INNER JOIN t1 on t1.tag=t2.tag GROUP BY t1.cardid, t1.name

the result come out like this:

cardid      name       record
100         Dan        09:00
100         Dan        10:00
200         Jane       06:00
200         Jane       09:00
399         Lisa       07:00
399         Lisa       13:00
500         Kane       10:00
500         Kane       12:10
500         Kane       13:50

Now I add a 'min' filter and modify the syntax to become like this:

SELECT t1.cardid, t1.Name, min(t2.record) As Record
FROM t2 INNER JOIN t1 on t1.tag=t2.tag GROUP BY t1.cardid, t1.name

The result become like this:

cardid      name       record
100         Dan        09:00
200         Jane       06:00
399         Lisa       07:00
500         Kane       10:00

How do I add a filter so that only the 'minimum value' of each record that has more than; say '08:00' value come out in the "record" column. The result I want is something like this:

cardid      name       record
100         Dan        09:00
500         Kane       10:00

I'm using SQL.

Answer 1

SELECT t1.cardid, t1.Name, min(t2.record) As Record
FROM t2 INNER JOIN t1 on t1.tag=t2.tag
GROUP BY t1.cardid, t1.name
having min(t2.record) >= cast('08:00' as time)

I suppose record is also time type, also you can use convert('08:00', time) or even try without cast/convert, it can work too, as mysql can do automatic casting

for very old mysql you can try to use having 0+substring(t2.record, 1,2) >= 8