Moving PS 1.6.0.9 running on PHP 5.5 to PHP 7.4

[TC!!]

I'm looking after the hosting for a very old PS site which I didn't develop.
I'm being forced to move them to a new hosting company but the minimum PHP they offer is 7.4.

I found this chart which explains PS versions and PHP compatibility:
https://devdocs.prestashop.com/1.7/basics/installation/system-requirements/
I spent all day yesterday trying to gently upgrade the site with the 1 click upgrade while updating the PHP version as I go:

PHP 5.5 -> PHP 5.6
PS 1.6.0.9 -> 1.6.1.24
PS 1.6.1.24 -> PS 1.7.5.2
PHP 5.6 -> PHP 7.0

I'm tearing my hair out, even the first simple 1.6 update failed and I had to manually trigger the database update.
The big move to 1.7.5.2 failed with a cryptic PHP message about a function expecting 2 parameters, I had to make the PHP change from 5.6 to 7.0 1st for it to work.

But no matter what I do as soon as I get near a PS 1.7 version I get Error 500s. It keeps complaining about pSQL() being defined twice in config/alias.php and classes/Db.php. When I look at the files for 1.7.5.2 I can see classes/Db.php isn't there any more and instead classes/DB/Db.php.

So it looks like the upgrade process is leaving behind old files that aren't needed any more and are causing conflicts.

I've tried doing this on the live site and a local docker environment but I keep hitting a brick wall.

Edited May 31, 2022 by TC!! (see edit history)

[catzarov]

Hello, I ran into the same problem in early April. My boss asked me to switch from 1.6.1.21 to 1.7.8.5
Of course I got into big movies and dramas like you.
My decision was this: I installed a clean install of 1.7.8.5 then used the migrate module to transfer all the old information to the new site.
It was hard to believe, but everything went smoothly and without problems. The process of registering the product images slowed down a bit. About 6 hours for 1500 products. Eventually, however, it turned out that some of the purchased modules that were important for my boss to work again turned out to be incompatible with the new version. Unfortunately I threw a lot of hard work to the wind, but at least I will know in the future if I need to move the store, how to do it without risks. Keep it as "one in mind" my idea, if you find no other solution resort to it. The module we bought was relatively cheap at 79 euros. 

I wish you luck and a quick solution.

[PrestaHeroes USA]

On 5/31/2022 at 4:54 AM, catzarov said:

Hello, I ran into the same problem in early April. My boss asked me to switch from 1.6.1.21 to 1.7.8.5
Of course I got into big movies and dramas like you.
My decision was this: I installed a clean install of 1.7.8.5 then used the migrate module to transfer all the old information to the new site.
It was hard to believe, but everything went smoothly and without problems. The process of registering the product images slowed down a bit. About 6 hours for 1500 products. Eventually, however, it turned out that some of the purchased modules that were important for my boss to work again turned out to be incompatible with the new version. Unfortunately I threw a lot of hard work to the wind, but at least I will know in the future if I need to move the store, how to do it without risks. Keep it as "one in mind" my idea, if you find no other solution resort to it. The module we bought was relatively cheap at 79 euros. 

I wish you luck and a quick solution.

 

excellent advice, or simply just upgrade.

you will never succeed upgrading all the php to newer level of php

don't try

simply move to hosting that allows you full control of what php you use....they exist.