Fix serialized data broken due to editing MySQL database in a text editor?

Question

Background: I downloaded a *.sql backup of my WordPress site's database, and replaced all instances of the old database table prefix with a new one (e.g. from the default wp_ to something like asdfghjkl_).

I've just learnt that WordPress uses serialized PHP strings in the database, and what I did will have messed with the integrity of the serialized string lengths.

The thing is, I deleted the backup file just before I learnt about this (as my website was still functioning fine), and installed a number of plugins since. So, there's no way I can revert back, and I therefore would like to know two things:

1. How can I fix this, if at all possible?

2. What kind of problems could this cause?

(This article states that, a WordPress blog for instance, could lose its settings and widgets. But this doesn't seem to have happened to me as all the settings for my blog are still intact. But I have no clue as to what could be broken on the inside, or what issues it'd pose in the future. Hence this question.)

Answer 1

Visit this page: http://unserialize.onlinephpfunctions.com/

On that page you should see this sample serialized string: a:1:{s:4:"Test";s:17:"unserialize here!";}. Take a piece of it-- s:4:"Test";. That means "string", 4 characters, then the actual string. I am pretty sure that what you did caused the numeric character count to be out of sync with the string. Play with the tool on the site mentioned above and you will see that you get an error if you change "Test" to "Tes", for example.

What you need to do is get those character counts to match your new string. If you haven't corrupted any of the other encoding-- removed a colon or something-- that should fix the problem.