table name->city table name->history
id city id history
---------------- -----------------------
1 mumbai 1 Lorem ipsum Amet
2 delhi 2 Lorem ipsum Amet
3 chennai
4 patna
5 ranchi
6 noida预期输出:-
city hisoty history_id
------------------------------------------------------
mumbai Lorem Ipsum Amet 1
delhi Lorem Ipsum Amet 2
chennai
patna
ranchi
noida请帮我查询以获得预期的输出
最佳答案
执行 LEFT OUTER JOIN 就像
select c.city,
coalesce(h.history,''),
coalesce(h.id,'') as history_id
from city c
left join history h on c.id = h.id;
关于mysql - 从两个不同的表中获取数据，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35451983/