help ordering database rows in php urgent!

busby

i have table in my database holding food items.

i need users to be able to order those items individually for example...if apples are third from the top..they should be able to move them up or down the list 1 place at a time perhaps with an up and down arrow.

i have a field in my table called item_order

the only problem is...users are going to be able to insert new items to the database...but i dont know how they can populate the order field...i cant set it to auto increment because the item_id is the primary key auto incrementing...how can i populate the order field?

and then once i have this problem sorted how do i then allow users to change this order?

im looking for code if possible please because ive spent WAY to long on this now and im struggling to grasp things people advise me to do. terminology and methods of accomplishing this are just going over my head.

please help.

busby

ok heres maybe a better way of putting it.

i have a table in a database..i want users to be able to order it from the front end.

so i put an order_id field in the table

now...users can add new data to this table so how do i populate this order_id field? does the user input an id when they input the other data? because it wont let me use auto increment as i already have my primary key set to auto increment.

how do i populate this field? this is urgent i need help

laserlight

Inserting MAX(order_id)+1 might work for you.

busby

thankyou i gave up on the ordering to continue with rest of project but will go back to it now you said that...thanks

busby

just thought id say that inserting max(catid)+1 didnt work i get an error saying:

"invalid use of group function"

i dont know what that means but it doesnt work anyway

i still havnt solved it so if anyone could please help still id appreciate it

laserlight

busby wrote:
just thought id say that inserting max(catid)+1 didnt work i get an error saying:

"invalid use of group function"

i dont know what that means but it doesnt work anyway

Ah, use a subquery instead, e.g., (SELECT MAX(item_order)+1 FROM FoodItems).