Would like to learn how to Run a SQL Query

[GunsNetwork]

Database mysql
Error
SQL-query :

ALTER TABLE post ADD proxyip VARCHAR(255) not null AFTER ipaddress

MySQL said:

Table 'mysql.post' doesn't exist

So I guess what now, when you said enter it there is no:

Run SQL query/queries on database animeuto_forum [Documentation] :

So what else do I need to do to add this!

Need some help please.

Thanks