To remove any post that is older than X days in WordPress you can use the query below.
Sample mySQL
DELETE FROM wp_posts WHERE post_type = 'post' AND DATEDIFF(NOW(), post_date) > X
admin
How to give a user admin rights in mySql
To give a user admin rights in MySql you can use the following snippet.
Sample mySql Query
GRANT ALL PRIVILEGES ON myDbName.* TO 'myUserName'@'%' WITH GRANT OPTION;
How to change default Admin Username in WordPress
Every default WordPress installation will create an account with a default Admin username. This can be a security issue.
To change default Admin Username in WordPress you can use the mySql snippet below.
UPDATE wp_users SET user_login = 'NewUsername' WHERE user_login = 'Admin';