将多行合并为表中的单行

Question

So I'm working on a simple IN/OUT board system to keep track of who enters and leaves and grabs a picture of them.

I have each IN/OUT going to an access table.

access

id	user_id	datetime	direction	image
4	1	5/6/2021 16:04	In	1-1621019890.png
5	1	5/8/2021 13:25	Out	1-1621019891.png
9	1	5/10/2021 16:14	In	1-1621019892.png
12	1	5/11/2021 13:58	Out	1-1621019893.png
15	1	5/11/2021 14:02	In	1-1621019894.png
22	1	5/11/2021 14:31	Out	1-1621019895.png
25	1	5/11/2021 14:32	In	1-1621019896.png
26	1	5/11/2021 14:34	Out	1-1621019897.png
28	1	5/11/2021 15:02	In	1-1621019898.png
29	1	5/11/2021 15:04	Out	1-1621019899.png
32	1	5/11/2021 15:04	In	1-1621019880.png
33	1	5/11/2021 18:09	Out	1-1621019870.png
34	1	5/11/2021 19:05	In	1-1621019860.png
35	1	5/14/2021 19:16	Out	1-1621019808.png
38	1	5/14/2021 19:18	In	1-1621019888.png
39	1	5/14/2021 19:19	Out	1-1621019967.png

I'm trying to locate a SQL query that will output something similar to this:

User_id	In	in-image	Out	out-image	Total Time
1	5/6/2021 16:04	1-1621019890.png	5/8/2021 13:25	1-1621019891.png
1	5/10/2021 16:14	1-1621019892.png	5/11/2021 13:58	1-1621019893.png
1	5/11/2021 14:02	1-1621019894.png	5/11/2021 14:31	1-1621019895.png
1	5/11/2021 14:32	1-1621019896.png	5/11/2021 14:34	1-1621019897.png
1	5/11/2021 15:02	1-1621019898.png	5/11/2021 15:04	1-1621019899.png
1	5/11/2021 15:04	1-1621019880.png	5/11/2021 18:09	1-1621019870.png
1	5/11/2021 19:05	1-1621019860.png	5/14/2021 19:16	1-1621019808.png
1	5/14/2021 19:18	1-1621019888.png	5/14/2021 19:19	1-1621019967.png

It would be great if I could also get it to calculate the total time in but worst case I can do that in PHP.

From doing a lot of searching it would appear that I would need to setup a PIVOT in my MySQL query but not seeing how to do that with multiple columns.

Answer 1

Provided your data are regular (no missihng Out row for an In row)

select user_id, 
   max(case when direction='In' then datetime end) in,
   max(case when direction='In' then image end) in_image,
   max(case when direction='Out' then datetime end) out,
   max(case when direction='Out' then image end)    out_image
from (select *,
         row_number() over(partition by user_id, direction order by datetime) rn
      from yourtable) t
group by user_id, rn

Answer 2

Thanks to David784 for the direction.

I ended up creating a new table called accessgroups which just has 2 columns in_id and out_id. This will allow me to group together 2 access entries. I can then use that to do a SQL join to get the output exactly how I'd like.

SELECT access.user_id,access.datetime as 'IN',access.image as 'IN_IMAGE',(SELECT datetime from access WHERE id = accessgroup.out_id) as 'OUT',(SELECT image from access WHERE id = accessgroup.out_id) as 'OUT_IMAGE' 
FROM `access` 
INNER JOIN accessgroup 
ON access.id = accessgroup.in_id 
WHERE direction = 1

Now I just have to modify my webapp to create that row in accessgroups when you sign in and update it with the signout id. And I'll just use PHP to calculate the difference in IN/OUT times.