Error codes/messages reveal information about table structure

create database db;

create table db.t (a int, b int);

create user foo;

grant select (a) on db.t to foo;

--connect (con1,localhost,foo,,)

select a from db.t;

--error ER_COLUMNACCESS_DENIED_ERROR

select b from db.t;

select c from db.t;

# Cleanup

--disconnect con1

--connection default

drop database db;

drop user foo;

MariaDB [test]> select b from db.t;

ERROR 1143 (42000): SELECT command denied to user 'foo'@'localhost' for column 'b' in table 't'

MariaDB [test]> select c from db.t;

ERROR 1054 (42S22): Unknown column 'c' in 'field list'