use mysql;
insert db (db,user,select_priv) values ('foo','dwr_foo','Y'), ('bar','dwr_bar','Y');
insert roles_mapping (user,role) values ('dwr_qux_dev','dwr_foo'),('dwr_qux_dev','dwr_bar');
insert ignore user (user,show_db_priv,is_role) values ('dwr_foo','N','Y'), ('dwr_bar','N','Y'), ('dwr_qux_dev','Y','Y');
Warnings:
Warning	1364	Field 'ssl_cipher' doesn't have a default value
Warning	1364	Field 'x509_issuer' doesn't have a default value
Warning	1364	Field 'x509_subject' doesn't have a default value
Warning	1364	Field 'authentication_string' doesn't have a default value
flush privileges;
drop role dwr_foo;
drop role dwr_bar;
drop role dwr_qux_dev;
use test;
create table db_copy as select * from mysql.db;
delete from mysql.db;
flush privileges;
create user u1@localhost;
create role r1;
create role r2;
grant r1 to u1@localhost;
grant select on test.* to r2;
grant select on m_.* to r2;
grant r2 to r1;
show grants for u1@localhost;
Grants for u1@localhost
GRANT r1 TO 'u1'@'localhost'
GRANT USAGE ON *.* TO 'u1'@'localhost'
show grants for r1;
Grants for r1
GRANT r2 TO 'r1'
GRANT USAGE ON *.* TO 'r1'
GRANT USAGE ON *.* TO 'r2'
GRANT SELECT ON `test`.* TO 'r2'
GRANT SELECT ON `m_`.* TO 'r2'
drop user u1@localhost;
drop role r1, r2;
insert mysql.db select * from db_copy;
flush privileges;
drop table db_copy;