You could also use https://ww.wp.xz.cn/plugins/better-search-replace/ .
Or HeidiSQL for example, to find/replace.
In addition to @tobiasbg, remember the escaped characters!
I was running Find/Replace to convert all my href’s in TablePress
From: http, www, absolute
To: https, non-www, relative
So it looked something like:
Find: http:\/\/www.website.com\/
Replace: \/
Then I just amended under wp_options the siteurl and home
From: http://www.website.com
To: https://website.com
