How can I view all those users and their "Grants" for an entire table?

Question

If I have a table called example. And I grant privileges like SELECT, INSERT, etc to subject1, subject2, subject3. How can I then as the owner of the table, view everyone and their privileges that I have given to example?

Answer 1

You could run a query against tables_priv table in the mysql database:

SELECT p.User
     , p.Host
     , p.Table_priv
     , p.Grantor
  FROM mysql.tables_priv p
 WHERE p.Db         = 'mydatabase'
   AND p.Table_name = 'example'
 ORDER by 1,2,3

This isn't everyone that has privileges on the table, if privileges were granted on the entire database, e.g.

GRANT SELECT ON mydatabase.* TO subject1@'%'  

Those privileges would be in the db table in the mysql database. Global privileges granted to a user on all databases would be in the user table.

Answer 2

The MySql schema for users and privileges is pretty vast complicated depending on how in depth you would like to get.

You can find all users from the users table (granted you have permissions). And you may find table/column privileges from these two columns: tables_priv and columns_priv

so you would want something like this:

select * from users
join tables_priv on users.user = tables_priv.user

Take note that the more information you want, the more you will need to expand this query.