msyql命令實例(持續更新)
阿新 • • 發佈:2017-12-26
查詢兩個表差集1、插入數據
insert into co_user(mailbox_id,domain_id,realname,engname,oabshow,showorder,eenumber,gender,birthday,homepage,tel_mobile,tel_home,tel_work,tel_work_ext,tel_group,im_qq,im_msn,addr_country,addr_state,addr_city,addr_address,addr_zip,remark,last_session,last_login,openid,unionid,wx_id) values('$mailbox_id','$domain_id','testdel2','NULL','1','0','NULL','male','0000-00-00','NULL','NULL','NULL','NULL','NULL','NULL','NULL','NULL','NULL','NULL','NULL','NULL','NULL','NULL','NULL','NULL','0','0','0');
2、查詢兩個表mailbox_id的差集。
select * from core_mailbox where mailbox_id not in (select mailbox_id from co_user);
備註(大神方法):
好吧!這個是可以,但是數據多了的話,想到這個查詢的邏輯有點受不住
於是再改為下面的這樣:
select cu.mailbox_id,cm.mailbox_id co_user as cu left join core_mailbox as cm on cu.mailbox_id = cm.mailbox_id where cm.mailbox_id NULL;
利用了left join的,然後進行對比,並且利用where進行篩選。
後面也在網上找了這條:
SELECT mailbox_id FROM `co_user` left join (select mailbox_id as i from core_mailbox) as t1 on co_user.mailbox_id= t1.i where t1.i is NULL;
概念上與第二條同理。
LEFT JOIN 關鍵字會從左表 (table_name1) 那裏返回所有的行,即使在右表 (table_name2) 中沒有匹配的行。
msyql命令實例(持續更新)