how to change theme wordpress by database code example
Example: change active theme wordpress from database
1. Click the field option_value for template
2. Replace the current theme with a default theme, like twentysixteen.
3. Press enter to save.
4. Do the same for stylesheet.
refrence:
https://help.one.com/hc/en-us/articles/115005585909-Change-your-WordPress-theme-from-the-database