Question

I’m creating this app where it’s important to register if a person is active or not on the current day. My table structure looks like this:

| Field     | Type        | Null | Key | Default           | Extra          |
+-----------+-------------+------+-----+-------------------+----------------+
| id        | int(11)     | NO   | PRI | NULL              | auto_increment | 
| kid_id    | int(11)     | NO   |     | NULL              |                | 
| status    | varchar(50) | NO   |     | NULL              |                | 
| timestamp | timestamp   | NO   |     | CURRENT_TIMESTAMP |                | 

What’s important for me; is to select only values with timestamp equal to the current day. Next I need to check if the latest status is “active” or “inactive” of course based on kid_id. What I’ve figured out so far is this.

SELECT kid_id , status , timestamp FROM actions WHERE date(timestamp) = CURDATE() ORDER BY timestamp DESC;

Which returns these values:

+--------+----------+---------------------+
| kid_id | status   | timestamp           |
+--------+----------+---------------------+
|      4 | active   | 2010-08-23 12:10:03 | 
|      3 | inactive | 2010-08-23 10:53:18 | 
|      3 | active   | 2010-08-23 10:53:10 | 
+--------+----------+---------------------+

Only problem now is that i receive both the active and inactive status with “kid_id” = “3”.
So my question is how do i only select the latest status from each kid_id.

In advance thank you very much for your help. It’s appreciated.

———- EDIT

I’ll try to make my point a little more clear.

This is my table as it looks right now…

+--------+----------+---------------------+
| kid_id | status   | timestamp           |
+--------+----------+---------------------+
|      3 | inactive | 2010-08-23 18:32:19 | 
|      4 | active   | 2010-08-23 12:10:03 | 
|      3 | active   | 2010-08-23 10:53:10 | 
+--------+----------+---------------------+
3 rows in set (0.00 sec)

I want to retrieve these values and only these

|      3 | inactive | 2010-08-23 18:32:19 | 
|      4 | active   | 2010-08-23 12:10:03 |

All of the solutions suggested below returns these values:

|      4 | active   | 2010-08-23 12:10:03 | 
|      3 | active   | 2010-08-23 10:53:10 |

By the way… Thanks for all the responses so soon I’m really grateful for all the help.

Answer 1

I’ve been out the office today. In the mean time I’ve figured out a way to solve my problem. I used a subselect which worked.

In the end my code looks a little like ovais.tariq‘s

Here is my solution:

SELECT * 
            FROM (
                SELECT * FROM actions 
                AS a
                WHERE date(timestamp) = curdate() 
                AND timestamp = (
                    SELECT max(timestamp) 
                    FROM actions 
                    AS b
                    WHERE a.kid_id = b.kid_id
                    )
                )
            AS c

Thanks everyone for your help 🙂