Question

Scenario: WAMP server, InnoDB Table, auto-increment Unique ID field [INT(10)], 100+ concurrent SQL requests. VB.Net should also be used if needed.

My database has an auto-increment field wich is used to generate a unique ticket/protocol number for each new information stored (service order).

The issue is that this number must be reseted each year. I.e. it starts at 000001/12 on 01/01/2012 00:00:00 up to maximum 999999/12 and then at 01/01/2013 00:00:00 it must start over again to 000001/13.

Obviously it should easly acomplished using some type of algorithm, but, I’m trying to find a more efficient way to do that. Consider:

1. It must (?) use auto-increment since the database has some concurrency (+100).

2. Each ticket must be unique. So 000001 on 2012 is not equal to 000001 on 2013.

3. It must be automatic. (no human interaction needed to make the reset, or whatever)

4. It should be reasonably efficient. (a watch program should check the database daily (?) but it seems not the best solution since it will ‘fail‘ 364 times to have success only once).

The ‘best’ approach I could think of is to store the ticket number using year, such as:

12000001 – 12999999 (it never should reach the 999.999, anyway)

and then an watch program should set the auto increment field to 13000000 at 01/01/2013.

Any Suggestions?

PS: Thanks for reading… 😉

Answer 1

So, for futher reference I’ve adopted the following sollution:

I do create n tables on the database (one for each year) with only one auto-increment field wich is responsible to generate the each year unique id.

So, new inserts are done into the corresponding table considering the event date. After that the algorithm takes the last_inseted_id() an store that value into the main table using the format 000001/12. (ticket/year)

That because each year must have it’s own counter since an 2012 event would be inserted even when the current date is already 2013.

That way events should be retroactive, no reset is needed and it’s simple to implement.

Sample code for insertion:

$eventdate="2012-11-30";
$eventyear="2012";
$sql = "INSERT INTO tbl$eventyear VALUES (NULL)";
mysql_query ($sql);
$sql = "LAST_INSERT_ID()";
$row = mysql_fetch_assoc(mysql_query($sql));
$eventID = $row(0)
$sql = "INSERT INTO tblMain VALUES ('$eventID/$eventYear', ... ";
mysql_query($sql)