String constant length in db

Hello! Sorry if question is silly, but I can’t google an answer.

Sometimes we need to replace one text constant to another in the whole db, for example when we move site to another domain. The best way I know is to make db dump, edit it as a text document and upload to db again.

Sometimes constants look like this:

(178, 18, 'page', 'http://dvascheta.ru/contacts'),

and here is no problem, but sometimes like this:

a:5:{s:4:"home";s:19:"http://dvascheta.ru";s:4:"link";

And here is a problem because “s:19” means that a 19 chars long string follows.

Today I moved my site to httpS and had to replace all “http” to “https”. As soon as I did it, I found out that my theme settings were set to defaults (it forgot header and background image, all widgets etc). I found out that the problem was in string length and I had to correct string length everywhere. I.e. changing “http://dvascheta.ru” to “https://dvascheta.ru” I had also to change “s:19” to “s:20”

It was very much work to do because domain name was the part of very different strings of different length. I couldn’t use autoreplacement and had to change every occasion manually.

I noticed this length a long time ago and as soon as I remember I made string replacement without correcting length and everything was ok earlier. But now I’ve got a problem.

So the questions are:
1) What’s the sense of this length and what part of WP uses it?
2) Do you know any good automated way to replace constants and correct length?

Thanks in advance!

• This topic was modified 9 years, 3 months ago by Alexey.
• This topic was modified 9 years, 3 months ago by bdbrown.