mysql表合并

2019独角兽企业重金招聘Python工程师标准>>>

create or replace view v_action(id , type , time)   
as  
select id , 3 , ptime as time from photo  
union all  
select id , 4 , ctime as time from comment  
union all  
select id , type , atime as time from action

转载于:https://my.oschina.net/thinkinginc/blog/59692