mysql 增删改查
作者:互联网
mysql表内容操作
表内容操作无非就是增删改查,当然用的最多的还是查,而且查这一块东西最多,用起来最难,当然对于大神来说那就是so easy了,对于我这种小白还是非常难以灵活运用的,下面咱来一一操作一下
1、增
insert into 表 (列名,列名...) values (值,值,...) insert into 表 (列名,列名...) values (值,值,...),(值,值,值...) insert into 表 (列名,列名...) select (列名,列名...) from 表
例:
insert into tab1(name,email) values('zhangyanlin','zhangyanlin8851@163.com')
2、删
delete from 表 # 删除表里全部数据 delete from 表 where id=1 and name='zhangyanlin' # 删除ID =1 和name='zhangyanlin' 那一行数据
3、改
update 表 set name = 'zhangyanlin' where id>1
4、查
select * from 表 select * from 表 where id > 1 select nid,name,gender as gg from 表 where id > 1
查这块的条件太多太多我给列举出来至于组合还得看大家的理解程度哈
a、条件判断where
select * from 表 where id > 1 and name != 'aylin' and num = 12; select * from 表 where id between 5 and 16; select * from 表 where id in (11,22,33) select * from 表 where id not in (11,22,33) select * from 表 where id in (select nid from 表)
b、通配符like
select * from 表 where name like 'zhang%' # zhang开头的所有(多个字符串) select * from 表 where name like 'zhang_' # zhang开头的所有(一个字符)
c、限制limit
select * from 表 limit 5; - 前5行 select * from 表 limit 4,5; - 从第4行开始的5行 select * from 表 limit 5 offset 4 - 从第4行开始的5行
d、排序asc,desc
select * from 表 order by 列 asc - 根据 “列” 从小到大排列 select * from 表 order by 列 desc - 根据 “列” 从大到小排列 select * from 表 order by 列1 desc,列2 asc - 根据 “列1” 从大到小排列,如果相同则按列2从小到大排序
e、分组group by
select num from 表 group by num select num,nid from 表 group by num,nid select num,nid from 表 where nid > 10 group by num,nid order nid desc select num,nid,count(*),sum(score),max(score),min(score) from 表 group by num,nid select num from 表 group by num having max(id) > 10 特别的:group by 必须在where之后,order by之前
标签:name,改查,nid,num,mysql,增删,where,id,select 来源: https://www.cnblogs.com/itzhangmeng2299/p/16364562.html