As we know Magento database are very complex, so not easy to change Magento 2 admin password from database.
I am going to explain short technique how to change Magento 2 admin password from database.
Open admin_user table from database and paste this query on sql editor.
Please read below instruction before paste query.
Please make sure your admin username is admin or anything else, change username = ‘admin’ if admin username is not admin.
After fire this query your admin password will be set admin123. Replace admin123 if you want to set another.
Please make sure not included any space between random character and new password.
UPDATE mg_admin_user SET password = CONCAT(SHA2(‘abcdefghadmin123’, 256), ‘:abcdefgh:1’) WHERE username = ‘admin’