第五章 SQL语句

一、sql语句的语义

DDL：Data Definition Language   #数据定义语言 （create、alter）
DCL：Data Control Language	   #数据控制语言 （grant、revoke、commit、rollback）
DML：Data Manipulate	Language   #数据操作语言 （insert、delete、update）
DQL：Data Query Language		   #数据查询语言 （select、desc）

二、DDL --数据定义语言

1. create 操作库

1）查看语法

mysql> help create database;
Syntax:
CREATE {DATABASE | SCHEMA} [IF NOT EXISTS] db_name [create_specification] ...

create_specification:
    [DEFAULT] CHARACTER SET [=] charset_name | [DEFAULT] COLLATE [=] collation_name

2）创建库

#1.建库
mysql> create database db01;
Query OK, 1 row affected (0.00 sec)

#2.建库2
mysql> create schema db02;
Query OK, 1 row affected (0.00 sec)

#3.创建已存在的库不报错
mysql> create database db01;
ERROR 1007 (HY000): Can't create database 'db01'; database exists

mysql> create database IF NOT EXISTS db01;
Query OK, 1 row affected, 1 warning (0.00 sec)

3）查看建库语句

mysql> show create database db01;
+----------+-----------------------------------------------------------------+
| Database | Create Database                                                 |
+----------+-----------------------------------------------------------------+
| db01     | CREATE DATABASE `db01` /*!40100 DEFAULT CHARACTER SET latin1 */ |
+----------+-----------------------------------------------------------------+
1 row in set (0.00 sec)

4）创建库指定字符集和校验规则

#1.指定字符集建库
mysql> create database db03 character set utf8;
Query OK, 1 row affected (0.00 sec)

#2.指定字符集和校验规则建库
mysql> create database db04 character set utf8 collate utf8_general_ci;
Query OK, 1 row affected (0.00 sec)

mysql> create database db06 charset utf8 collate utf8_general_ci;
Query OK, 1 row affected (0.00 sec)

5）修改库

#只需要修改字符集和校验规则
mysql> alter database db05 character set utf8mb4 collate utf8mb4_general_ci;
Query OK, 1 row affected (0.00 sec)

mysql> show create database db05;
+----------+------------------------------------------------------------------+
| Database | Create Database                                                  |
+----------+------------------------------------------------------------------+
| db05     | CREATE DATABASE `db05` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ |
+----------+------------------------------------------------------------------+
1 row in set (0.00 sec)

6）删库

mysql> drop database db05;
Query OK, 0 rows affected (0.00 sec)

2. create 操作表

1）查看语法

mysql> help create table;
Syntax:
CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
    (create_definition,...)
    [table_options]
    [partition_options]

CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
    [(create_definition,...)]
    [table_options]
    [partition_options]
    [IGNORE | REPLACE]
    [AS] query_expression

CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
    { LIKE old_tbl_name | (LIKE old_tbl_name) }

2）建表

#1.进入库
mysql> use test;
Database changed

#2.查看所在库
mysql> select database();
+------------+
| database() |
+------------+
| test      |
+------------+
1 row in set (0.00 sec)

#3.建表
mysql> create table tb1(id int);
Query OK, 0 rows affected (0.01 sec)

3）数据类型

int			整数			-2^31 --- 2^31-1   (-2147483648 - 2147483647)
tinyint		最小整数	    -128 --- 127	  #一般用在定义年龄
varchar		字符类型（变长）	#身份证或者名字
char		字符类型（定长）
enum		枚举类型		  #性别
datetime	时间类型

4）测试int数据类型

#1.建表
mysql> create table tb1(id int);
Query OK, 0 rows affected (0.01 sec)

#2.指定字符集建表
mysql> create table tb2(id int) charset utf8;
Query OK, 0 rows affected (0.01 sec)

#3.查看建表语句
mysql> show create table tb2;
+-------+---------------------------------------------------------------------------------------+
| Table | Create Table                                                                          |
+-------+---------------------------------------------------------------------------------------+
| tb2   | CREATE TABLE `tb2` (
  `id` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
+-------+---------------------------------------------------------------------------------------+
1 row in set (0.01 sec)

#4.查看表结构
mysql> desc tb1;
+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id    | int(11) | YES  |     | NULL    |       |
+-------+---------+------+-----+---------+-------+
1 row in set (0.00 sec)

#5.插入数据
mysql> insert tb1 values('11111111111');
ERROR 1264 (22003): Out of range value for column 'id' at row 1

mysql> insert tb1 values('-2147483648');
Query OK, 1 row affected (0.00 sec)

mysql> insert tb1 values('2147483648');
ERROR 1264 (22003): Out of range value for column 'id' at row 1

mysql> insert tb1 values('-2147483649');
ERROR 1264 (22003): Out of range value for column 'id' at row 1

mysql> insert tb1 values('2147483647');
Query OK, 1 row affected (0.00 sec)
#原因：插入的数据超过数据类型的长度

5）测试char和varchar类型

#1.建表
mysql> create table tb1(id int,name varchar(12));
Query OK, 0 rows affected (0.06 sec)

#2.插入数据
mysql> insert into tb1 values('1','邱导');
Query OK, 1 row affected (0.00 sec)

mysql> insert into tb1 values('1','zengzhigaoxiang');
ERROR 1136 (21S01): Column count doesn't match value count at row 1
#字符超过数据类型的限制值

6）测试enum类型

#1.建表
mysql> create table tb4(id int,name varchar(10),sex enum('man','woman'));
Query OK, 0 rows affected (0.03 sec)

#2.插入数据
mysql> insert into tb4 values('1','邱导','man');
Query OK, 1 row affected (0.00 sec)

mysql> insert into tb4 values('2','刘大维','nan');
ERROR 1265 (01000): Data truncated for column 'sex' at row 1
#如果是枚举类型，必须插入类型指定的值，不能插入额外的值

7）建表测试

#建学生表
id
name
sex
age
cometime

#1.建表
mysql> create table student(id int,name varchar(10),sex enum('男','nv'),age tinyint,cometime datetime);
Query OK, 0 rows affected (0.03 sec)

#2.插入数据
mysql> insert into student values('-12573','邱导','男','-18',now());
Query OK, 1 row affected (0.00 sec)

#3.查看数据
mysql> select * from student;
+--------+--------+------+------+---------------------+
| id     | name   | sex  | age  | cometime            |
+--------+--------+------+------+---------------------+
| -12573 | 邱导   | 男   |  -18 | 2020-10-23 18:40:15 |
+--------+--------+------+------+---------------------+
1 row in set (0.00 sec)

8）建表的数据属性

not null： 			非空
primary key： 		主键（唯一且非空的）
auto_increment： 	自增（此列必须是：primary key或者unique key）
unique key： 		唯一键（单独的唯一的）
default： 			默认值
unsigned： 			非负数
comment：			注释

9）加上数据属性建表

#1.建表
mysql> create table student(
    -> id int unsigned primary key auto_increment comment '学生id',
    -> name varchar(10) not null comment '学生姓名',
    -> sex enum('男','女') default '男' comment '学生性别',
    -> age tinyint unsigned comment '学生年龄',
    -> cometime datetime default now() comment '入学时间',
    -> class varchar(12) not null comment '学生班级',
    -> status enum('0','1') default 1 comment '学生状态');
Query OK, 0 rows affected (0.01 sec)

#2.查看建表语句
mysql> show create table student;
                                                                         
| student | CREATE TABLE `student` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT '学生id',
  `name` varchar(10) NOT NULL COMMENT '学生姓名',
  `sex` enum('男','女') DEFAULT '男' COMMENT '学生性别',
  `age` tinyint(3) unsigned DEFAULT NULL COMMENT '学生年龄',
  `cometime` datetime DEFAULT CURRENT_TIMESTAMP COMMENT '入学时间',
  `class` varchar(12) NOT NULL COMMENT '学生班级',
  `status` enum('0','1') DEFAULT '0' COMMENT '学生状态',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8                              |

1 row in set (0.00 sec)

#3.插入数据
mysql> insert into student(name,class) values('邱导','Linux10期');
Query OK, 1 row affected (0.00 sec)
mysql> insert into student(name,class) values('刘大维','Linux10期');
Query OK, 1 row affected (0.00 sec)
mysql> insert into student(name,class) values('虞陈宇','Linux10期');
Query OK, 1 row affected (0.00 sec)
mysql> insert into student(name,age,class) values('周昊','18','Linux10期');
Query OK, 1 row affected (0.00 sec)

#4.查看数据
mysql> select * from student;
+----+-----------+------+------+---------------------+------------+--------+
| id | name      | sex  | age  | cometime            | class      | status |
+----+-----------+------+------+---------------------+------------+--------+
|  1 | 邱导      | 男   | NULL | 2020-10-23 19:06:25 | Linux10期  | 0      |
|  2 | 邱导      | 男   | NULL | 2020-10-23 19:07:31 | Linux10期  | 0      |
|  3 | 刘大维    | 男   | NULL | 2020-10-23 19:07:57 | Linux10期  | 0      |
|  4 | 虞陈宇    | 男   | NULL | 2020-10-23 19:08:17 | Linux10期  | 0      |
|  5 | 周昊      | 男   |   18 | 2020-10-23 19:09:44 | Linux10期  | 0      |
+----+-----------+------+------+---------------------+------------+--------+
5 rows in set (0.00 sec)

10）删除表

mysql> drop table student;
Query OK, 0 rows affected (0.00 sec)

11）修改表

#1.修改表字符集
mysql> alter table play charset utf8mb4;
Query OK, 0 rows affected (0.03 sec)
Records: 0  Duplicates: 0  Warnings: 0

#2.修改表名
mysql> alter table play rename student;
Query OK, 0 rows affected (0.01 sec)

#3.给表插入字段
mysql> alter table student add name varchar(10);

#4.给表插入多个字段
mysql> alter table student add sex enum('男','女'),add age tinyint;

#5.插入字段到第一列
mysql> alter table student add id int first;

#6.插入字段到指定字段后面
mysql> alter table student add class varchar(12) after id;

#7.删除字段
mysql> alter table student drop qiudao;

#8.修改列属性
mysql> alter table student modify name varchar(20);

#9.修改列的名字和属性
mysql> alter table student change sex xingbie enum('男','女');

三、DCL--数据控制语言

1.授权命令 grant

#1.授权
grant all on *.* to root@'172.16.1.%' identified by '123';
#应该授权低一点的权限
grant select,update,insert on database.* to dev@'172.16.1.%' identified by 'Lhd@123456'

#2.查看用户权限
mysql> show grants for root@'localhost';

#3.特殊权限授权
max_queries_per_hour：一个用户每小时可发出的查询数量
max_updates_per_hour：一个用户每小时可发出的更新数量

max_connections_per_hour：一个用户每小时可连接到服务器的次数
mysql> grant all on *.* to lhd@'localhost' identified by '123' with max_connections_per_hour 1;

max_user_connections：允许同时连接数量
mysql> grant all on *.* to test@'localhost' identified by '123' with max_user_connections 2;

2.回收权限 revoke

#1.回收权限
mysql> revoke drop on *.* from test@'localhost';

#2.查看权限
mysql> show grants for test@'localhost';

#3.所有权限
SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, GRANT, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, SUPER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE TABLESPACE

3.授权一个超级管理员

mysql> grant all on *.* to superuser@'localhost' identified by 'Lhd@123456' with grant option;

四、DML--数据操作语言

1.insert命令

#1.插入数据之前先看表结构
mysql> desc student;
+----------+---------------------+------+-----+-------------------+----------------+
| Field    | Type                | Null | Key | Default           | Extra          |
+----------+---------------------+------+-----+-------------------+----------------+
| id       | int(10) unsigned    | NO   | PRI | NULL              | auto_increment |
| name     | varchar(10)         | NO   |     | NULL              |                |
| sex      | enum('男','女')     | YES  |     | 男                |                |
| age      | tinyint(3) unsigned | YES  |     | NULL              |                |
| cometime | datetime            | YES  |     | CURRENT_TIMESTAMP |                |
| class    | varchar(12)         | NO   |     | NULL              |                |
| status   | enum('0','1')       | YES  |     | 0                 |                |
+----------+---------------------+------+-----+-------------------+----------------+
7 rows in set (0.00 sec)

#2.insert不规范写法
mysql> insert student values('4','周昊','男','20','2020-10-23','Linux10','0');
#一个字段都不能少

#3.规范的写法（只插入需要的值）
mysql> insert student(name,class) values('邱导','linux10');
mysql> insert student(name,class,age) values('邱导','linux10',20);

#4.规范写法插入多条数据
mysql> insert student(name,class,age) values('增加','linux10',20),('减少','linux10',30);

2.update语句

#1.修改数据之前一定要确认数据
mysql> select * from student;

#2.修改数据，错误写法
mysql> update student set age='16';

#3.修改数据，正确写法
mysql> update student set age='18' where id=1;

#4.如果说就是修改表中所有数据
mysql> update student set age='18' where 1=1;

3.delete语句

#1.错误语法
mysql> delete from student;

#2.正确写法
mysql> delete from student where id=1;

#3.删除
mysql> delete from student where name='增加' and cometime='2020-10-23 20:16:57';

#4.使用状态列表示已删除
mysql> update student set status='1' where id=9;
mysql> select * from student where status='0';

4.注意

1.操作数据时一定要查看数据
2.修改和删除数据时一定要加条件
3.使用条件时尽量使用主键字段
4.如果没有主键字段，使用多条件的方式
5.如果有状态列，使用状态列表示数据已删除

五、作业：

1.需求：

1.恢复快照，使用二进制的方式搭建三台数据库
2.创建数据库
3.创建学生表（使用数据类型和数据属性）
4.将自己组的同学插入学生表

2.环境准备

主机名	IP地址	角色
db01	10.0.0.51	数据库服务器
db02	10.0.0.52	数据库服务器
db03	10.0.0.53	数据库服务器

3.db01配置

1.上传包
[root@db01 ~]# rz

2.安装依赖
[root@db01 ~]# yum install -y ncurses-devel libaio-devel cmake glibc autoconf gcc-c++

3.解压
[root@db01 ~]# tar xf mysql-5.6.42-linux-glibc2.12-x86_64.tar.gz

4.创建自定义目录
[root@db03 ~]# mkdir /service

5.移动并改名
[root@db01 ~]# mv mysql-5.6.42-linux-glibc2.12-x86_64 /service/mysql-5.6.42

6.做软连接
[root@db01 ~]# ln -s /service/mysql-5.6.42 /service/mysql

7.创建用户
[root@db01 ~]# useradd mysql -s /sbin/nologin -M

8.拷贝启动文件和配置文件
[root@db01 ~]# cd /service/mysql/support-files/
[root@db01 /service/mysql/support-files]# cp my-default.cnf /etc/my.cnf
cp: overwrite '/etc/my.cnf'? y
[root@db01 /service/mysql/support-files]# cp mysql.server /etc/init.d/mysqld
​```

9.初始化
[root@db01 ~]# cd /service/mysql/scripts/
[root@db01 /service/mysql/scripts]# ./mysql_install_db --user=mysql --basedir=/service/mysql --datadir=/service/mysql/data

10.配置system管理启动MySQL
[root@db01 ~]# vim /usr/lib/systemd/system/mysqld.service
[Unit]
Description=MySQL Server
Documentation=man:mysqld(8)
Documentation=https://dev.mysql.com/doc/refman/en/using-systemd.html
After=network.target
After=syslog.target
[Install]
WantedBy=multi-user.target
[Service]
User=mysql
Group=mysql
ExecStart=/service/mysql/bin/mysqld_safe --defaults-file=/etc/my.cnf
LimitNOFILE = 5000

[root@db01 ~]# systemctl daemon-reload
	
11.修改启动文件
[root@db01 ~]# vim /etc/init.d/mysqld 
basedir=/service/mysql
datadir=/service/mysql/data
	
12.启动s数据库
[root@db01 ~]# systemctl start mysqld

13.设置环境变量
[root@db01 ~]# vim /etc/profile.d/mysql.sh
export PATH=/service/mysql/bin:$PATH

[root@db01 ~]# source /etc/profile

14.设置数据库密码
[root@db02 ~]# mysqladmin -uroot password
New password: 
Confirm new password: 

4.db02配置

配置1.上传包
[root@db02 ~]# rz

2.安装依赖
[root@db02 ~]# yum install -y ncurses-devel libaio-devel cmake glibc autoconf gcc-c++

3.解压
[root@db02 ~]# tar xf mysql-5.6.42-linux-glibc2.12-x86_64.tar.gz

4.创建自定义目录
[root@db03 ~]# mkdir /service

5.移动并改名
[root@db02 ~]# mv mysql-5.6.42-linux-glibc2.12-x86_64 /service/mysql-5.6.42

6.做软连接
[root@db02 ~]# ln -s /service/mysql-5.6.42 /service/mysql

7.创建用户
[root@db02 ~]# useradd mysql -s /sbin/nologin -M

8.拷贝启动文件和配置文件
[root@db02 ~]# cd /service/mysql/support-files/
[root@db02 /service/mysql/support-files]# cp my-default.cnf /etc/my.cnf
cp: overwrite '/etc/my.cnf'? y
[root@db02 /service/mysql/support-files]# cp mysql.server /etc/init.d/mysqld
​```

9.初始化
[root@db02 ~]# cd /service/mysql/scripts/
[root@db02 /service/mysql/scripts]# ./mysql_install_db --user=mysql --basedir=/service/mysql --datadir=/service/mysql/data

10.配置system管理启动MySQL
[root@db02 ~]# vim /usr/lib/systemd/system/mysqld.service
[Unit]
Description=MySQL Server
Documentation=man:mysqld(8)
Documentation=https://dev.mysql.com/doc/refman/en/using-systemd.html
After=network.target
After=syslog.target
[Install]
WantedBy=multi-user.target
[Service]
User=mysql
Group=mysql
ExecStart=/service/mysql/bin/mysqld_safe --defaults-file=/etc/my.cnf
LimitNOFILE = 5000

[root@db02 ~]# systemctl daemon-reload
	
11.修改启动文件
[root@db02 ~]# vim /etc/init.d/mysqld 
basedir=/service/mysql
datadir=/service/mysql/data
	
12.启动s数据库
[root@db02 ~]# systemctl start mysqld

13.设置环境变量
[root@db02 ~]# vim /etc/profile.d/mysql.sh
export PATH=/service/mysql/bin:$PATH

[root@db02 ~]# source /etc/profile

14.设置数据库密码
[root@db02 ~]# mysqladmin -uroot password
New password: 
Confirm new password: 

5.db03配置

配置1.上传包
[root@db03 ~]# rz

2.安装依赖
[root@db03 ~]# yum install -y ncurses-devel libaio-devel cmake glibc autoconf gcc-c++

3.解压
[root@db03 ~]# tar xf mysql-5.6.42-linux-glibc2.12-x86_64.tar.gz

4.创建自定义目录
[root@db03 ~]# mkdir /service

5.移动并改名
[root@db03 ~]# mv mysql-5.6.42-linux-glibc2.12-x86_64 /service/mysql-5.6.42

6.做软连接
[root@db03 ~]# ln -s /service/mysql-5.6.42 /service/mysql

7.创建用户
[root@db03 ~]# useradd mysql -s /sbin/nologin -M

8.拷贝启动文件和配置文件
[root@db03 ~]# cd /service/mysql/support-files/
[root@db03 /service/mysql/support-files]# cp my-default.cnf /etc/my.cnf
cp: overwrite '/etc/my.cnf'? y
[root@db03 /service/mysql/support-files]# cp mysql.server /etc/init.d/mysqld
​```

9.初始化
[root@db03 ~]# cd /service/mysql/scripts/
[root@db03 /service/mysql/scripts]# ./mysql_install_db --user=mysql --basedir=/service/mysql --datadir=/service/mysql/data

10.配置system管理启动MySQL
[root@db03 ~]# vim /usr/lib/systemd/system/mysqld.service
[Unit]
Description=MySQL Server
Documentation=man:mysqld(8)
Documentation=https://dev.mysql.com/doc/refman/en/using-systemd.html
After=network.target
After=syslog.target
[Install]
WantedBy=multi-user.target
[Service]
User=mysql
Group=mysql
ExecStart=/service/mysql/bin/mysqld_safe --defaults-file=/etc/my.cnf
LimitNOFILE = 5000

[root@db03 ~]# systemctl daemon-reload
	
11.修改启动文件
[root@db03 ~]# vim /etc/init.d/mysqld 
basedir=/service/mysql
datadir=/service/mysql/data
	
12.启动s数据库
[root@db03 ~]# systemctl start mysqld

13.设置环境变量
[root@db03 ~]# vim /etc/profile.d/mysql.sh
export PATH=/service/mysql/bin:$PATH

[root@db03 ~]# source /etc/profile

14.设置数据库密码
[root@db03 ~]# mysqladmin -uroot password
New password: 
Confirm new password: 

5.db01配置想关需求

1.创建数据库
mysql> create database jh charset utf8;
Query OK, 1 row affected (0.00 sec)

2.使用数据库
mysql> use jh;
Database changed

3.创建数据表
mysql> create table student(
    -> id int unsigned primary key auto_increment comment '学生id',
    -> name varchar(10) not null comment '学生姓名',
    -> sex enum('male','female') default 'male' comment '学生性别',
    -> age tinyint unsigned comment '学生年龄',
    -> writer_time datetime default now() comment '录入时间',
    -> class varchar(12) not null comment '学生班级',
    -> status enum('0','1') default '1' comment '学生状态'
    -> );
Query OK, 0 rows affected (0.14 sec)

4.将数据录入数据表
mysql>  insert into student
    -> (id,name,age,class)
    -> values
    -> ('1','金辉','24','Linux10期');
Query OK, 1 row affected (0.00 sec)

mysql> select * from student;
+----+--------+------+------+---------------------+------------+--------+
| id | name   | sex  | age  | writer_time         | class      | status |
+----+--------+------+------+---------------------+------------+--------+
|  1 | 金辉   | male |   24 | 2020-10-23 19:15:03 | Linux10期  | 1      |
+----+--------+------+------+---------------------+------------+--------+
1 row in set (0.00 sec)

mysql>   insert into student
    ->   (name,class,age)
    ->   values
    ->   ('高峰','Linux10期','28'),
    ->   ('马冸东','Linux10期','26'),
    ->   ('虞陈宇','Linux10期','22'),
    ->   ('王安峰','Linux10期','24'),
    ->   ('李铮林','Linux10期','22'),
    ->   ('李富豪','Linux10期','24'),
    ->   ('刘永华','Linux10期','26'),
    ->   ('陈立帆','Linux10期','21'),
    ->   ('刘大维','Linux10期','22'),
    ->   ('崔鹏','Linux10期','22'),
    ->   ('张智晨','Linux10期','23'),
    ->   ('李子龙','Linux10期','25')
    ->   ;

mysql> select * from student;
+----+-----------+------+------+---------------------+------------+--------+
| id | name      | sex  | age  | writer_time         | class      | status |
+----+-----------+------+------+---------------------+------------+--------+
|  1 | 金辉      | male |   24 | 2020-10-23 19:15:03 | Linux10期  | 1      |
|  2 | 高峰      | male |   28 | 2020-10-23 19:29:15 | Linux10期  | 1      |
|  3 | 马冸东    | male |   26 | 2020-10-23 19:29:15 | Linux10期  | 1      |
|  4 | 虞陈宇    | male |   22 | 2020-10-23 19:29:15 | Linux10期  | 1      |
|  5 | 王安峰    | male |   24 | 2020-10-23 19:29:15 | Linux10期  | 1      |
|  6 | 李铮林    | male |   22 | 2020-10-23 19:29:15 | Linux10期  | 1      |
|  7 | 李富豪    | male |   24 | 2020-10-23 19:29:15 | Linux10期  | 1      |
|  8 | 刘永华    | male |   26 | 2020-10-23 19:29:15 | Linux10期  | 1      |
|  9 | 陈立帆    | male |   21 | 2020-10-23 19:29:15 | Linux10期  | 1      |
| 10 | 刘大维    | male |   22 | 2020-10-23 19:29:15 | Linux10期  | 1      |
| 11 | 崔鹏      | male |   22 | 2020-10-23 19:29:15 | Linux10期  | 1      |
| 12 | 张智晨    | male |   23 | 2020-10-23 19:29:15 | Linux10期  | 1      |
| 13 | 李子龙    | male |   25 | 2020-10-23 19:29:15 | Linux10期  | 1      |
+----+-----------+------+------+---------------------+------------+--------+
13 rows in set (0.00 sec)