To view current setup, neet to run this
SELECT *
FROM wp_options
WHERE option_name = 'template'
OR option_name = 'stylesheet'
OR option_name = 'current_theme';
To change to default or other setup run this on sql
UPDATE wp_options SET option_value = 'default' WHERE option_name = 'template';
UPDATE wp_options SET option_value = ‘default’ WHERE option_name = ‘stylesheet’;
UPDATE wp_options SET option_value = ‘default’ WHERE option_name = ‘current_theme’;