Query last 20 entries

[lance]

Or 10 or whatever number you want to display (not all). I\'m new to all this wonderful PHP MySQL stuff and would like to display a table of the last 20 entries made. To be more specific it\'s a PIREP reporting system for pilots to submit their flight hours, destination, etc...

 

I can\'t display all, but would like to be able to display the last 20 or so pireps in a table.

 

I AM Able to query the database and display ALL records, but that page will be come waaaaaaaaaay to large very fast ;-)

 

Thanks for any help or any links you could provide to tutorials that might help me understand how to do this.

[effigy]

use the limit feature at the end of your query. e.g.: select * from table limit 20

[dammitjanet]

just to expand of effigy\'s post you can do this.

 

select count(*) from table;

 

and stick it in a variable called $max ... and subtract 20 from it.

 

then make your query string

\"select * from table limit $max,-1\"

 

which should give you the last 20 lines of the table.

 

you may want to stipulate an order by clause on a datetime field or unique incremental to make sure the data is the last 20 entries.

[gizmola]

Mysql\'s limit feature is one of the really nice things it offers. That\'s definately the way to go. Hopefully you have a key to the table using auto_increment, or have a timestamp column. Then you would not have to bother with trying to get the count(*) and do a limit count(*)-20, and would instead simply do:

 

SELECT * FROM Table ORDER BY Table_id DESC LIMIT 20;

 

This will display the rows most recent first. May be what you want, and saves an extra query.