一、创建表
1.创建表
CREATE TABLE cre_uer (
id INT(10) NOT NULL PRIMARY KEY,
maner VARCHAR(20) ,
sex VARCHAR(10),
age INT(4),
city VARCHAR(30),
worker VARCHAR(40),
marker INT(10)); // cre_uer是表名
2.复制表
create table copyuser select * from cre_user; (创建一张和cre_uer一样的表) //copyuser是表名
二、删除表
drop table copyuser;//copyuser是表名
三、插入表
1.插入表
insert into cre_uer (id,maner,sex,age,city,worker,marker)values(1,'张三','女',23,'杭州','会计',9)
2.插入查询出来的输入
insert into cre_uer(id,maner,sex,age)select id,maner,sex,age from cre_uer;
四、查询语句
1.查询整张表
select * from cre_uer;
2.排序查询
select * from cre_uer order by id decs;//id倒序排列 acs正序排列
3.查询marker的和
select sum(marker) as summarker from cre_uer;
4.查询marker平均值
select avg(marker)as avgmarker from cre_uer;
5.查询最大值
select max(marker) maxmarker form cre_uer;
6.查询最小值
select min(marker)minmarker from cre_uer;
五、删除表数据
delete from test_management.`cre_uer` where marker is null; //删除cre_uer表中marker为null的的数据
delete from test_management.`cre_uer` where city='洛阳' //删除cre_uer表中 city为洛阳的数据