sql

1.create table rxqtest (sno int(10),name varchar(20))

2.insert into rxqtest(sno,name)values(1,'rxq')

3.select * from rxqtest

4.update rxqtest set sno =2 where sno =1

5.delete from rxqtest where snp =2

6.create index rxq_index ON rxqtest(sno)

7.show index from rxqtest

8.select A.* from A left join/inner join /right join  B on A.id =B.id

9.group by 分组 order by 排序

10.case colum when value1 then value2 else value3 end 

11.delete drop truncate 

12.in not in exits not exits distinct

13.count sum avg  

14.select sno,name from rxqtest group by sno,name  //根据两个条件分组

15.alter table rxqtest add A int(10) 添加字段A 数据类型为int(10)

16.alter table rxqtest drop A 

17.mysql -h ip -uroot -p

18.mysqldump -h ip -u root -p password --all-databases >> xxx.sql