You don't have to change anything in the database. Follow these steps:
Activate a default WordPress theme (e.g.
twentyseventeen) - that is any theme other than the child theme you are going to rename.
Rename your child Themes folder name and child theme's name in
Now activate the child theme.
That's all, WordPress will update related info. in the Database autometically.
Note: You've already figured out step-2 correctly. Just need to follow step-1 before step-2 and then step-3 afterwards. That's all.
It's also possible to change the theme name from the database after following step-2 above. Sometimes it's helpful in case you've already changed the theme name & now can't access the site because WordPress has a different theme name in the Database.
In this case, know that WordPress saves two values in the
wp_options table. One is with the
stylesheet and the other one is the
If it's not a child theme, then both the values are same. For a child theme however,
stylesheet will have
template will have
So if you change these two values accordingly, it'll work as well. You can use PHPMyAdmin, or the following MySQL query:
update wp_options set option_value = 'new-child-theme-name' where option_name = 'stylesheet';
update wp_options set option_value = 'parent-theme-name' where option_name = 'template';
parent-theme-name accordingly in the above query.