php - mysql 连接查询两表的所有字段

Question

policy(策略表)
policy_id,（策略编号）
hero_id,(参考Friends表中的hero_id)
friend_id,(参考Friends表中的hero_id)

friends(好友表)
hero_id,
hero_name,
hero_level

-----------------------华丽分割线----------------------

Answer 1

select a.*,b.* form policy a,friends b limit 1

Answer 2

select * from policy a left join friends b on a.xx=b.xx(ab关系字段)