Look at the Database Layer

Look at the Database Layer
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When you create a database table, you are doing under the alias you assume when logging in to the db client program. This alias the hold ALL permissions for the dattabase, table, and whatever you create.

All permissions include all privileges, ie

execute
select|insert|update|delete
references including create/drop permissions for foreign key constraints
trigger

Please refer to the mysql documentation, particularly figure 6.2 for full scope of ALL.

That is a hell of a lot of permissions for programs that really just need to have select permission in order to display some content. What do we do about that?

A program should identify itself as some user other than the owner, or it get's the owner's permissions. This means
that other user must be granted the necessary permissions,
ideally the minimally necessary permissions
Assume the program is the user nobody then
```
grant select on table17 to nobody;
```
is quite enough for most programs
Then the page that the user uses to create new posts in the forum, must have what rights? None, exactly, quite correct! The program called by submission of the form, however, must have insert permission:
```
grant insert on table17 to nobody;
```

Just to remind you, once rights are granted, they can only be taken away by the revoke declaration such as in

revoke insert on table17 from nobody;

In this way, and only in this way, you can be sure that even if you have security breaches in your authentication, the database is vulnetrable only as far as the programs' permissions.

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