I am designing a database that will be implemented in mysql
and will have a website frontend.

short description:
a kind of auction/second hand site where people give away stuff they don't need (anymore) FOR FREE!
The owners will not be able to get money for their item.
the owners have the choice between 3 possibilities though:
1 really give it away for free.
2 the new owner will have to make a donation of minimum X euro to a good cause
3 the new owner will have to make a donation of minimum X euro to a good cause specified by the first owner

normal chain of events

userA puts item in db
userB puts in an appeal for the item
userA grants the appeal and
if minimum donation is asked:
userB pays for the good cause
userB gets the item
item is set as given away.

this is what I am thinking of making as a db:
see give-away.gif
Am I making any serious mistakes?
Or does anyone have a suggestion?
I havn't designed many databases and I would like to do this one correctly...

tables:
user:
the registerd person on my site
he can put up an ITEM to give away (I this case he can grant the appeal to another person for his item)
or put in an APPEAL to get an ITEM

item:
the ITEM to be given away
with an extra option to donate money to a good CAUSE
this will have a min. amount and maybe a restriction/suggestion on to what cause the amount is to be given (AMOUNT,CHOICE and CAUSE)

cause:
the actual good cause like amnesty international or WWF and the like

appeal:
USERS that would like a certain ITEM can put in an APPEAL for that item.
the owner of the ITEM can then decide out of all the appeals who he will grant the item to.

Why not check to see if this hasn't been done already first - I use freecycle to do exactly what your aiming for. There are active groups set up all around the world with items either offered or wanted and payments can optionally be suggested for charities. I received a great piano using the site just last week.

If you still want to go ahead and build another site that offers just the same features then why not just send them a wanted post and ask for their database design? I don't think they make any money from the site but it's still a very positive thing to provide to the world. If you have any new ideas then why not speak to them and develop it for them?

I habe been surfing for about 2 weeks now looking for a site like that, and didn't' find it. that's why I thought, hey, then I'll make it.

the fact I didn't find it after surfing for 2 weeks seems strange to me.

tnx for the link! (though at first sight it seems a bit dissapointing)

Local groups are set up as yahoo groups which then send out emails to all their members as what's being offered and what's being requested. It works in a rough way but I'm sure you could implement a better interface. Whether or not people would then come to your site depends on the inertia that people feel when they're on a working site already. I have had emails for sites offering improved services but never felt the need because most people use this site. I'd suggest joining a local group and offering something. You could still contact them and offer them your services if you want to help but I doubt they'd pay.

who said anything about paying?
I am not in it to earn money, just like to make it ( and a bonus is when it actually get's used!)
off course a dream of mine is that some company would pay money for a small advert on a site I made. but that will defenatly not happen on the site I would make here so that is clearly not the goal...

Good luck with whatever you try. I must admit I've tried building loads of web sites from tools that check web sites for mistakes to new types of database and even new languages. I enjoyed writing them all but can't say I've made much at it, c'est la vie.