how a unique url is made for each category & product?

hi all !
i want to know how a unique url is made for each category & product in opencart?

for example, my first category in 1.4.x version has such a url:
http://127.0.0.1:8888/index.php?route=p ... ry&path=20
while the first category in 1.5.x has this one:
ttp://127.0.0.1:8888/index.php?route=product/category&path=25

both category have the same number of product and priority.
but the urls are different!

It depends on the ID of the category in your database. Doesn't really matters.

MarketInSG wrote:It depends on the ID of the category in your database. Doesn't really matters.

i want to upgrade my 1.4.x version to 1.5.2.2 vesion
it is very important for me to keep the product urls in the new site. i don't want to lose my google indexed urls.
so how can i do it?

If you update, you won't lose anything. As long as you update properly, that is..

MarketInSG wrote:If you update, you won't lose anything. As long as you update properly, that is..

oh! sorry for this fault! i wanted to have two shop.
i should have said clean installation.

i want to install the 1.5.2.2 version in another host. then try to make the unique urls. and finally change the dns ip address of my domain keeper to new site. after that a new domain for old shop could be assigned.
that's all.

That's something unique. Then I will say you will have to manually modify your database for the categories ID.