SQL - Select between 3 tables

I have 3 tables:

hosts (host_id, name, address, template_id);
hostgroup (hostgroup_id, name);
hosts_hostgroup (a, b);

The first table keeps all the hosts, th开发者_运维技巧e second one all the groups and the last one says which group belong each host.

Note that hosts_hostgroup has two different column names a and b.

Which is the Query to give me the hosts that belong to some group?

SELECT h.*
FROM hosts h 
INNER JOIN hosts_hostgroup hg ON hg.host_id = h.host_id
INNER JOIN hostgroup g ON g.hostgroup_id = hg.hostgroup_id
WHERE g.name = 'mygroupname'

SELECT hosts.* FROM hosts
INNER JOIN hosts_hostgroup ON hosts.host_id=hosts_hostgroup.a
WHERE hosts_hostgroup.b=(some id);