据个例子给你 表a(id,name) 1 a 2 b 表b(name,sex) a nan c nvname是两表连接的条件 内连接(a inner join b)结果 id name sex 1 a nan左连接(a left join b)结果 id name sex 1 a nan 2 b (null)右连接(a right join b)结果 id name sex 1 a nan (null) c nv全连接(a full join b)结果 id name sex 1 a nan 2 b (null) (null) c nv
和右(外)连接 right outer join 等同于 right join全连接 full join
据个例子给你
表a(id,name)
1 a
2 b
表b(name,sex)
a nan
c nvname是两表连接的条件
内连接(a inner join b)结果
id name sex
1 a nan左连接(a left join b)结果
id name sex
1 a nan
2 b (null)右连接(a right join b)结果
id name sex
1 a nan
(null) c nv全连接(a full join b)结果
id name sex
1 a nan
2 b (null)
(null) c nv