Question

I work for a hosting company were we often get requests for installs, new domains, lag fixes etc. To get a bit of an overview of what is still open I decided to make a really simple ticket system. I have a bit of php knowledge and a bit of MySQL knowledge. For now we will be submitting the tickets ourselves based on e-mails and phonecalls from customers.

I have created the following SQL structure:

|| TICKETS  ||    || STATUSSES  ||    || STATUS-CODES  ||
--------------    ----------------    -------------------
| ID         |    |  ticket_id   |    | ID              |
| cust_name  |    |  status_id   |    | status_txt      |
| cust_cntct |    |  datetime    |    -------------------
| subject    |    ----------------
| message    |    
--------------     

I now want to make the overviw table showing all the existing tickets. A ticket is inserted with a default status. The concurring timestamp will be the time that the ticket was added. Every time a ticket moves to the next status a new status will be added with a timestamp. The newest status is always the current status.

I can’t figure out how to create a query that will get every ticket with its latest status. A simple join will return a ticket as many times as the amount of statusses it has. I want to create a join but only show the results were the timestamp of the status is the newest for a certain ticket.

Answer 1

Try this:

SELECT  a.*, b.`datettime`, d.status_txt
FROM    tickets a
            INNER JOIN statusses b
                on a.id = b.ticket_ID
            INNER JOIN
            (
                SELECT  ticket_ID, MAX(`datetime`) CurrentTicketDate
                FROM    Statuses
                GROUP BY ticket_ID
            ) c
                ON  b.ticket_ID = c.tecket_ID AND
                    b.`datetime` = c.CurrentTicketDate
            INNER JOIN Status_Codes d
                on b.status_ID = d.id