SELECT sys_block id sys_block name FROM sys_group sys_group2block sys_

SELECT sys_block.id, sys_block.name 
FROM `sys_group`, `sys_group2block`, `sys_block` 
WHERE (`sys_group`.id = `sys_group2block`.group_id AND `sys_block`.id = `sys_group2block`.block_id AND `sys_group`.id = 1)