左连接但是取随机值

Question

学习SQL。加入两个表后如何随机抽取样本？非常感谢。

select  *
from t1 
left join t2  on t1.ID = t2.ID

Answer 1

只需添加ORDER BY rand()和LIMIT样本大小（例如5）：

select  *
from t1 
left join t2  on t1.ID = t2.ID
ORDER BY rand()
LIMIT 5