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8.7-主从数据库的配置+mysql的增删改查

作者：代码探险家 | 2024-08-08 08:43:00

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一、mysql环境的配置

1.环境准备

（1）主数据库


#关闭防火墙
[root@master ~]# systemctl stop firewalld
 
#关闭selinux
[root@master ~]# setenforce 0
 
#下载lrzsz工具
[root@master ~]# yum -y install lrzsz
 
#安装rsync
[root@master ~]# yum -y install rsync
 
#查看是否安装了libaio
[root@master ~]# rpm -qa|grep libaio
libaio-0.3.109-13.el7.x86_64
 
#查看是否安装了rsync
[root@master ~]# rpm -qa|grep rsync
rsync-3.1.2-12.el7_9.x86_64

（2）从数据库


#关闭防火墙
[root@slave ~]# systemctl stop firewalld
 
#关闭selinux
[root@slave ~]# setenforce 0
 
#安装lrzsz
[root@slave ~]# yum -y install lrzsz
 
#安装rsync
[root@slave ~]# yum -y install rsync

2.解压

（1）主数据库


# 将mysqlmysql-8.0.33-linux-glibc2.12-x86_64.tar包拖到xshell中
[root@master ~]# rz -E
rz waiting to receive.
[root@master ~]# ls
anaconda-ks.cfg  mysql-8.0.33-linux-glibc2.12-x86_64.tar
 
# 解压
[root@master ~]# tar -xf mysql-8.0.33-linux-glibc2.12-x86_64.tar 
[root@master ~]# tar -xf mysql-8.0.33-linux-glibc2.12-x86_64.tar.xz
 
# 查看是否解压成功
[root@master ~]# ls
anaconda-ks.cfg
mysql-8.0.33-linux-glibc2.12-x86_64
mysql-8.0.33-linux-glibc2.12-x86_64.tar
mysql-8.0.33-linux-glibc2.12-x86_64.tar.xz
mysql-router-8.0.33-linux-glibc2.12-x86_64.tar.xz
mysql-test-8.0.33-linux-glibc2.12-x86_64.tar.xz

（2）从数据库


[root@slave ~]# ls
anaconda-ks.cfg  mysql-8.0.33-linux-glibc2.12-x86_64.tar
[root@slave ~]# tar -xf mysql-8.0.33-linux-glibc2.12-x86_64.tar 
[root@slave ~]# tar -xf mysql-8.0.33-linux-glibc2.12-x86_64.tar.xz 
[root@slave ~]# ls
anaconda-ks.cfg
mysql-8.0.33-linux-glibc2.12-x86_64
mysql-8.0.33-linux-glibc2.12-x86_64.tar
mysql-8.0.33-linux-glibc2.12-x86_64.tar.xz
mysql-router-8.0.33-linux-glibc2.12-x86_64.tar.xz
mysql-test-8.0.33-linux-glibc2.12-x86_64.tar.xz

3.备份文件

（1）主数据库

[root@master ~]# cp -r mysql-8.0.33-linux-glibc2.12-x86_64 /usr/local/mysql

（2）从数据库

[root@slave ~]# cp -r mysql-8.0.33-linux-glibc2.12-x86_64 /usr/local/mysql

4.创建目录和用户

（1）主数据库


[root@master ~]# cd /usr/local/mysql/
[root@master mysql]# ls
bin  docs  include  lib  LICENSE  man  README  share  support-files
[root@master mysql]# mkdir mysql-files
[root@master mysql]# ll
总用量 292
drwxr-xr-x.  2 root root   4096 8月   7 09:21 bin
drwxr-xr-x.  2 root root     38 8月   7 09:21 docs
drwxr-xr-x.  3 root root    282 8月   7 09:21 include
drwxr-xr-x.  6 root root    201 8月   7 09:21 lib
-rw-r--r--.  1 root root 284945 8月   7 09:21 LICENSE
drwxr-xr-x.  4 root root     30 8月   7 09:21 man
drwxr-xr-x.  2 root root      6 8月   7 09:22 mysql-files
-rw-r--r--.  1 root root    666 8月   7 09:21 README
drwxr-xr-x. 28 root root   4096 8月   7 09:21 share
drwxr-xr-x.  2 root root     77 8月   7 09:21 support-files
[root@master mysql]# id mysql
id: mysql: no such user
[root@master mysql]# useradd -r -s /sbin/nologin mysql
[root@master mysql]# id mysql
uid=997(mysql) gid=995(mysql) 组=995(mysql)
[root@master mysql]# echo $?
0

（2）从数据库


[root@slave ~]# mkdir /usr/local/mysql/mysql-files
[root@slave ~]# useradd -r -s /sbin/nologin mysql
[root@slave ~]# id mysql
uid=997(mysql) gid=995(mysql) 组=995(mysql)

5.修改权限

（1）主数据库


[root@master mysql]# chown mysql:mysql ./mysql-files/
[root@master mysql]# ll
总用量 292
drwxr-xr-x.  2 root  root    4096 8月   7 09:21 bin
drwxr-xr-x.  2 root  root      38 8月   7 09:21 docs
drwxr-xr-x.  3 root  root     282 8月   7 09:21 include
drwxr-xr-x.  6 root  root     201 8月   7 09:21 lib
-rw-r--r--.  1 root  root  284945 8月   7 09:21 LICENSE
drwxr-xr-x.  4 root  root      30 8月   7 09:21 man
drwxr-xr-x.  2 mysql mysql      6 8月   7 09:22 mysql-files
-rw-r--r--.  1 root  root     666 8月   7 09:21 README
drwxr-xr-x. 28 root  root    4096 8月   7 09:21 share
drwxr-xr-x.  2 root  root      77 8月   7 09:21 support-files

（2）从数据库


[root@slave ~]# chown mysql:mysql /usr/local/mysql/mysql-files
[root@slave ~]# ll /usr/local/mysql/
总用量 292
drwxr-xr-x.  2 root  root    4096 8月   7 10:07 bin
drwxr-xr-x.  2 root  root      38 8月   7 10:07 docs
drwxr-xr-x.  3 root  root     282 8月   7 10:07 include
drwxr-xr-x.  6 root  root     201 8月   7 10:07 lib
-rw-r--r--.  1 root  root  284945 8月   7 10:07 LICENSE
drwxr-xr-x.  4 root  root      30 8月   7 10:07 man
drwxr-xr-x.  2 mysql mysql      6 8月   7 10:11 mysql-files
-rw-r--r--.  1 root  root     666 8月   7 10:07 README
drwxr-xr-x. 28 root  root    4096 8月   7 10:07 share
drwxr-xr-x.  2 root  root      77 8月   7 10:07 support-files

6.删除配置文件

（1）主数据库

[root@master mysql]# rm -rf /etc/my.cnf

（2）从数据库

[root@slave ~]# rm -rf /etc/my.cnf

7.初始化

（1）主数据库


# 初始化  从数据库不能初始化
[root@master mysql]# ./bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql
2024-08-07T01:28:33.413323Z 0 [System][MY-013169] [Server] /usr/local/mysql/bin/mysqld (mysqld 8.0.33) initializing of server in progress as process 1701
2024-08-07T01:28:33.420601Z 1 [System][MY-013576] [InnoDB] InnoDB initialization has started.
2024-08-07T01:28:34.159124Z 1 [System][MY-013577] [InnoDB] InnoDB initialization has ended.
2024-08-07T01:28:35.485851Z 6 [Note][MY-010454] [Server] A temporary password is generated for root@localhost: CpjsNb1yO-fd
[root@master mysql]# ls /usr/local/mysql
bin   docs     lib      man          README  support-files
data  include  LICENSE  mysql-files  share
[root@master mysql]# ll
总用量 296
drwxr-xr-x.  2 root  root    4096 8月   7 09:21 bin
drwxr-x---.  7 mysql mysql   4096 8月   7 09:28 data
drwxr-xr-x.  2 root  root      38 8月   7 09:21 docs
drwxr-xr-x.  3 root  root     282 8月   7 09:21 include
drwxr-xr-x.  6 root  root     201 8月   7 09:21 lib
-rw-r--r--.  1 root  root  284945 8月   7 09:21 LICENSE
drwxr-xr-x.  4 root  root      30 8月   7 09:21 man
drwxr-xr-x.  2 mysql mysql      6 8月   7 09:22 mysql-files
-rw-r--r--.  1 root  root     666 8月   7 09:21 README
drwxr-xr-x. 28 root  root    4096 8月   7 09:21 share
drwxr-xr-x.  2 root  root      77 8月   7 09:21 support-files
 
[root@master mysql]# ./bin/mysql_ssl_rsa_setup --datadir=/usr/local/mysql/data

（2）从数据库

从数据库不能初始化

8.其他配置

（1）主数据库

[root@master mysql]# cp support-files/mysql.server /etc/init.d/mysql8

（2）从数据库

[root@slave ~]# cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql8

9.修改主数据库的my.cnf配置文件


#修改配置文件
[root@master mysql]# vim my.cnf
[mysqld]
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data
socket=/tmp/mysql.sock
port=3306
 
#启动mysql服务
[root@master mysql]# service mysql8 start
Starting MySQL.Logging to '/usr/local/mysql/data/master.err'.
. SUCCESS! 
 
#登录mysql
[root@master mysql]# ./bin/mysql -P3306 -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.33
 
Copyright (c) 2000, 2023, Oracle and/or its affiliates.
 
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql> alter user 'root'@'localhost' identified by 'Hui@2003';
 
Query OK, 0 rows affected (0.00 sec)
 
#退出
mysql> quit
Bye
 
#在my.cnf中继续添加内容
[root@master mysql]# vim my.cnf
[mysqld]
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data
socket=/tmp/mysql.sock
port=3306
 
log-error=/usr/local/mysql/data/db01-master.err
log-bin=/usr/local/mysql/data/binlog
server-id=10
character_set_server=utf8mb4
 
#启动服务
[root@master mysql]# service mysql8 start
Starting MySQL SUCCESS! 
 
#登录mysql
[root@master mysql]# ./bin/mysql -P3306 -pHui@2003
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 8.0.33 MySQL Community Server - GPL
 
Copyright (c) 2000, 2023, Oracle and/or its affiliates.
 
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
#退出
mysql> quit
Bye

10.查看主数据库中目录的信息


#查看data目录
[root@master mysql]# ls -l data/
总用量 90572
-rw-r-----. 1 mysql mysql       56 8月   7 09:28 auto.cnf
-rw-r-----. 1 mysql mysql      477 8月   7 09:40 binlog.000001
-rw-r-----. 1 mysql mysql       16 8月   7 09:37 binlog.index
-rw-------. 1 mysql mysql     1680 8月   7 09:28 ca-key.pem
-rw-r--r--. 1 mysql mysql     1112 8月   7 09:28 ca.pem
-rw-r--r--. 1 mysql mysql     1112 8月   7 09:28 client-cert.pem
-rw-------. 1 mysql mysql     1680 8月   7 09:28 client-key.pem
-rw-r-----. 1 mysql mysql   196608 8月   7 09:40 #ib_16384_0.dblwr
-rw-r-----. 1 mysql mysql  8585216 8月   7 09:28 #ib_16384_1.dblwr
-rw-r-----. 1 mysql mysql     5985 8月   7 09:28 ib_buffer_pool
-rw-r-----. 1 mysql mysql 12582912 8月   7 09:40 ibdata1
-rw-r-----. 1 mysql mysql 12582912 8月   7 09:37 ibtmp1
drwxr-x---. 2 mysql mysql     4096 8月   7 09:37 #innodb_redo
drwxr-x---. 2 mysql mysql      187 8月   7 09:37 #innodb_temp
-rw-r-----. 1 mysql mysql      929 8月   7 09:37 master.err
-rw-r-----. 1 mysql mysql        5 8月   7 09:37 master.pid
drwxr-x---. 2 mysql mysql      143 8月   7 09:28 mysql
-rw-r-----. 1 mysql mysql 25165824 8月   7 09:40 mysql.ibd
drwxr-x---. 2 mysql mysql     8192 8月   7 09:28 performance_schema
-rw-------. 1 mysql mysql     1676 8月   7 09:28 private_key.pem
-rw-r--r--. 1 mysql mysql      452 8月   7 09:28 public_key.pem
-rw-r--r--. 1 mysql mysql     1112 8月   7 09:28 server-cert.pem
-rw-------. 1 mysql mysql     1680 8月   7 09:28 server-key.pem
drwxr-x---. 2 mysql mysql       28 8月   7 09:28 sys
-rw-r-----. 1 mysql mysql 16777216 8月   7 09:39 undo_001
-rw-r-----. 1 mysql mysql 16777216 8月   7 09:40 undo_002
 
#查看错误日志
[root@master mysql]# cat data/master.err
2024-08-07T01:37:35.068359Z 0 [System][MY-010116] [Server] /usr/local/mysql/bin/mysqld (mysqld 8.0.33) starting as process 1925
2024-08-07T01:37:35.081787Z 1 [System][MY-013576] [InnoDB] InnoDB initialization has started.
2024-08-07T01:37:35.735592Z 1 [System][MY-013577] [InnoDB] InnoDB initialization has ended.
2024-08-07T01:37:36.273703Z 0 [Warning][MY-010068] [Server] CA certificate ca.pem is self signed.
2024-08-07T01:37:36.273749Z 0 [System][MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2024-08-07T01:37:36.306295Z 0 [System][MY-010931] [Server] /usr/local/mysql/bin/mysqld: ready for connections. Version: '8.0.33'  socket: '/tmp/mysql.sock'  port: 3306  MySQL Community Server - GPL.
2024-08-07T01:37:36.306366Z 0 [System][MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /tmp/mysqlx.sock
 
#查看/tmp中的套接字的信息
[root@master mysql]# ll /tmp
总用量 12
-rwx------. 1 root  root  836 8月   7 00:25 ks-script-pjA4To
srwxrwxrwx. 1 mysql mysql   0 8月   7 09:37 mysql.sock
-rw-------. 1 mysql mysql   5 8月   7 09:37 mysql.sock.lock
srwxrwxrwx. 1 mysql mysql   0 8月   7 09:37 mysqlx.sock
-rw-------. 1 mysql mysql   5 8月   7 09:37 mysqlx.sock.lock
drwx------. 3 root  root   17 8月   7 09:06 systemd-private-4192ed53ab514a048ba1c51132c3e28f-chronyd.service-skAuWy
drwx------. 3 root  root   17 8月   6 17:35 systemd-private-f93e9a7cc83a4e6ba1ea5a4ff1abcdc2-chronyd.service-2U7zsa
drwx------. 2 root  root    6 8月   7 00:25 vmware-root
-rw-------. 1 root  root    0 8月   7 00:21 yum.log

11.进行数据同步

（1）主数据库


#停止mysql服务
[root@master ~]# service mysql8 stop
Shutting down MySQL. SUCCESS! 
 
#删除/data中的auto.cnf
[root@master ~]# rm -rf /usr/local/mysql/data/auto.cnf 
 
#查看是否删除
[root@master ~]# ls /usr/local/mysql/data/
binlog.000001    client-key.pem     #innodb_redo  performance_schema  sys
binlog.index     #ib_16384_0.dblwr  #innodb_temp  private_key.pem     undo_001
ca-key.pem       #ib_16384_1.dblwr  master.err    public_key.pem      undo_002
ca.pem           ib_buffer_pool     mysql         server-cert.pem
client-cert.pem  ibdata1            mysql.ibd     server-key.pem
 
#将主数据库中的data同步到从数据库中
[root@master ~]# rsync -av /usr/local/mysql/data root@192.168.2.39:/usr/local/mysql

（2）从数据库


#在从库中查看有没有将data同步过来
[root@slave ~]# ls /usr/local/mysql
bin   docs     lib      man          README  support-files
data  include  LICENSE  mysql-files  share
 
#查看是否将主库data中的auto.cnf同步过来
[root@slave ~]# ls /usr/local/mysql/data
binlog.000001    client-key.pem     #innodb_redo  performance_schema  sys
binlog.index     #ib_16384_0.dblwr  #innodb_temp  private_key.pem     undo_001
ca-key.pem       #ib_16384_1.dblwr  master.err    public_key.pem      undo_002
ca.pem           ib_buffer_pool     mysql         server-cert.pem
client-cert.pem  ibdata1            mysql.ibd     server-key.pem

12.修改从数据库的my.cnf文件


[root@slave ~]# vim /usr/local/mysql/my.cnf
[mysqld]
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data
socket=/tmp/mysql.sock
 
log-error=/usr/local/mysql/data/err.log
relay-log=/usr/local/mysql/data/relaylog
character_set_server=utf8mb4
server-id=11

13.启动服务

（1）主数据库


[root@master ~]# service mysql8 start 
Starting MySQL.Logging to '/usr/local/mysql/data/db01-master.err'.
. SUCCESS!

（2）从数据库


[root@slave ~]# service mysql8 start 
Starting MySQL.Logging to '/usr/local/mysql/data/err.log'.
. SUCCESS!

14.将mysql添加到bin

（1）主数据库


#修改配置文件
[root@master ~]# vim /etc/profile
 
#在最后一行添加内容
export PATH=/usr/local/mysql/bin:$PATH
[root@master ~]# source /etc/profile
 
#尝试用mysql命令是否能进入
[root@master ~]# mysql -pHui@2003
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.33 MySQL Community Server - GPL
 
Copyright (c) 2000, 2023, Oracle and/or its affiliates.
 
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql>

（2）从数据库


#修改配置文件
[root@slave ~]# vim /etc/profile
 
#在最后一行添加内容
export PATH=/usr/local/mysql/bin:$PATH
 
[root@slave ~]# source /etc/profile
 
#尝试用mysql命令是否能进入
[root@slave ~]# mysql -h192.168.2.38 -uslave  --get-server-public-key -p
Enter password: slave_123;
 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 8.0.33 MySQL Community Server - GPL
 
Copyright (c) 2000, 2023, Oracle and/or its affiliates.
 
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql> quit
Bye

15.在主数据库中创建账号


#创建slave账户
mysql> create user 'slave'@'192.168.2.%' identified by 'slave_123;'；
Query OK, 0 rows affected (0.02 sec)
 
#给slave账户所有权限
mysql> grant replication slave on *.* to 'slave'@'192.168.2.%';
Query OK, 0 rows affected (0.02 sec)
 
#刷新权限
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
 
#防止数据被篡改，进行锁表
mysql> flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)
 
#查看主数据库的状态信息
mysql> show master status;
+---------------+----------+--------------+------------------+-------------------+
| File          | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+----------+--------------+------------------+-------------------+
| binlog.000002 |      878 |              |                  |                   |
+---------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

16.从数据库的配置


#获得远程主机master主机的公钥
[root@slave ~]# mysql -h192.168.2.38 -uslave  --get-server-public-key -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 8.0.33 MySQL Community Server - GPL
 
Copyright (c) 2000, 2023, Oracle and/or its affiliates.
 
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
#退出登录
mysql> quit
Bye
 
#启动mysql服务
[root@slave ~]# service mysql8 start
Starting MySQL SUCCESS! 
 
#登录本地的slave服务器数据库
[root@slave ~]# mysql -pHui@2003
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 8.0.33 MySQL Community Server - GPL
 
Copyright (c) 2000, 2023, Oracle and/or its affiliates.
 
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
 
mysql> change master to
    -> master_host='192.168.2.38',
    -> master_user='slave',
    -> master_password='slave_123;',
    -> master_port=3306,
    -> master_log_file='binlog.000002',
    -> master_log_pos=878;
Query OK, 0 rows affected, 9 warnings (0.03 sec)
 
#启动slave服务
mysql> start slave;
Query OK, 0 rows affected, 1 warning (0.02 sec)
 
#查看从服务器状态信息
mysql> show slave status\G

Slave_IO_Running和Slave_SQL_Running都是yes就表示主从数据库配置成功了

二、进行主从数据同步测试

（1）主数据库


#在主数据库上创建表，插入数据
#创建不了，是因为锁表
mysql> create database test;
ERROR 1223 (HY000): Can't execute the query because you have a conflicting read lock
 
#解锁
mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)
 
#创建库
mysql> create database test;
Query OK, 1 row affected (0.01 sec)
 
#使用数据库
mysql> use test;
Database changed
 
#创建student表
mysql> create table student(id int primary key,name varchar(45) not null,gender varchar(4) not null);
Query OK, 0 rows affected (0.02 sec)
 
#插入数据
mysql> insert into student values(1,'张三'，'男');
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '，'男')' at line 1
mysql> insert into student values(1,'张三','男');
Query OK, 1 row affected (0.03 sec)
 
mysql> insert into student values(2,'李四','男');
Query OK, 1 row affected (0.00 sec)
 
mysql> insert into student values(3,'王五','男');
Query OK, 1 row affected (0.00 sec)
 
mysql> insert into student values(4,'小凤仙','女');
Query OK, 1 row affected (0.00 sec)
 
#查看表中的数据
mysql> select * from student;
+----+-----------+--------+
| id | name      | gender |
+----+-----------+--------+
|  1 | 张三      | 男     |
|  2 | 李四      | 男     |
|  3 | 王五      | 男     |
|  4 | 小凤仙    | 女     |
+----+-----------+--------+
4 rows in set (0.00 sec)

（2）从数据库


#在从数据库上查看有没有同步主的数据库
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
+--------------------+
5 rows in set (0.01 sec)
 
#使用test数据库
mysql> use test;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
 
Database changed
 
#可以看到数据已经同步过来了
mysql> select * from student;
+----+-----------+--------+
| id | name      | gender |
+----+-----------+--------+
|  1 | 张三      | 男     |
|  2 | 李四      | 男     |
|  3 | 王五      | 男     |
|  4 | 小凤仙    | 女     |
+----+-----------+--------+
4 rows in set (0.01 sec)
 
可以看到数据都同步过来了

四、mysql语句的增删改查

MySQL语句

1.新增

insert into库名称.表名

(id,username,password) values(1,"abc","123")

insert into 表名称 values(1,"name","word")

insert into 表名称 select * from 其他表

insert into 表 value () ,()

2.删除

delete from 表名

delete from tablename where id=3

delete from tablename where age>8

delete from tablename where name on ("a","b","c");

3.修改

update mysql.user set host='%' where name='root'

update user set password='abc' where username="hui"

4.查询

select

练习

查询


mysql> use test;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
 
Database changed
mysql> select name from student;
+-----------+
| name      |
+-----------+
| 张三      |
| 李四      |
| 王五      |
| 小凤仙    |
+-----------+
4 rows in set (0.00 sec)
 
mysql> select id,gender from student;
+----+--------+
| id | gender |
+----+--------+
|  1 | 男     |
|  2 | 男     |
|  3 | 男     |
|  4 | 女     |
+----+--------+
4 rows in set (0.00 sec)
 
 
 
mysql> select a.*,b.* from student as a,student as b;
+----+-----------+--------+----+-----------+--------+
| id | name      | gender | id | name      | gender |
+----+-----------+--------+----+-----------+--------+
|  4 | 小凤仙    | 女     |  1 | 张三      | 男     |
|  3 | 王五      | 男     |  1 | 张三      | 男     |
|  2 | 李四      | 男     |  1 | 张三      | 男     |
|  1 | 张三      | 男     |  1 | 张三      | 男     |
|  4 | 小凤仙    | 女     |  2 | 李四      | 男     |
|  3 | 王五      | 男     |  2 | 李四      | 男     |
|  2 | 李四      | 男     |  2 | 李四      | 男     |
|  1 | 张三      | 男     |  2 | 李四      | 男     |
|  4 | 小凤仙    | 女     |  3 | 王五      | 男     |
|  3 | 王五      | 男     |  3 | 王五      | 男     |
|  2 | 李四      | 男     |  3 | 王五      | 男     |
|  1 | 张三      | 男     |  3 | 王五      | 男     |
|  4 | 小凤仙    | 女     |  4 | 小凤仙    | 女     |
|  3 | 王五      | 男     |  4 | 小凤仙    | 女     |
|  2 | 李四      | 男     |  4 | 小凤仙    | 女     |
|  1 | 张三      | 男     |  4 | 小凤仙    | 女     |
+----+-----------+--------+----+-----------+--------+
16 rows in set (0.00 sec)

创建可以远程登录的用户


mysql> create user 'haha'@'%' identified by 'Hui22003；'；
Query OK, 0 rows affected (0.00 sec)
 
mysql> grant all privileges on *.* to 'haha'@'%' ;
Query OK, 0 rows affected (0.01 sec)

远程登录：

统计


# 用来统计的，这三个没区别
 
mysql> select count(*) from student;
+----------+
| count(*) |
+----------+
|        4 |
+----------+
1 row in set (0.07 sec)
 
mysql> select count(1) from student;
+----------+
| count(1) |
+----------+
|        4 |
+----------+
1 row in set (0.06 sec)
 
mysql> select count(gender) from student;
+---------------+
| count(gender) |
+---------------+
|             4 |
+---------------+
1 row in set (0.05 sec)

别名


mysql> select id,name,gender from student;
+----+-----------+--------+
| id | name      | gender |
+----+-----------+--------+
|  1 | 张三      | 男     |
|  2 | 李四      | 男     |
|  3 | 王五      | 男     |
|  4 | 小凤仙    | 女     |
+----+-----------+--------+
4 rows in set (0.00 sec)
 
mysql> select id as 编号,name,gender from student;
+--------+-----------+--------+
| 编号   | name      | gender |
+--------+-----------+--------+
|      1 | 张三      | 男     |
|      2 | 李四      | 男     |
|      3 | 王五      | 男     |
|      4 | 小凤仙    | 女     |
+--------+-----------+--------+
4 rows in set (0.00 sec)
 
mysql> select id as 编号,name as 姓名,gender as 性别 from student;
+--------+-----------+--------+
| 编号   | 姓名      | 性别   |
+--------+-----------+--------+
|      1 | 张三      | 男     |
|      2 | 李四      | 男     |
|      3 | 王五      | 男     |
|      4 | 小凤仙    | 女     |
+--------+-----------+--------+
4 rows in set (0.00 sec)

数据分析的基础

1.排序

1.max

2.min

2.汇总

1.count

2.sum

3.avg

练习

排序


mysql> select * from student;
+----+-----------+--------+
| id | name      | gender |
+----+-----------+--------+
|  1 | 张三      | 男     |
|  2 | 李四      | 男     |
|  3 | 王五      | 男     |
|  4 | 小凤仙    | 女     |
+----+-----------+--------+
4 rows in set (0.00 sec)
 
 
 
按照性别排序
 
mysql> select * from student order by gender;
+----+-----------+--------+
| id | name      | gender |
+----+-----------+--------+
|  4 | 小凤仙    | 女     |
|  1 | 张三      | 男     |
|  2 | 李四      | 男     |
|  3 | 王五      | 男     |
+----+-----------+--------+
4 rows in set (0.00 sec)
 
按照性别进行降序/升序排序
 
mysql> select * from student order by gender desc;
+----+-----------+--------+
| id | name      | gender |
+----+-----------+--------+
|  1 | 张三      | 男     |
|  2 | 李四      | 男     |
|  3 | 王五      | 男     |
|  4 | 小凤仙    | 女     |
+----+-----------+--------+
4 rows in set (0.00 sec)
 
mysql> select * from student order by gender asc;
+----+-----------+--------+
| id | name      | gender |
+----+-----------+--------+
|  4 | 小凤仙    | 女     |
|  1 | 张三      | 男     |
|  2 | 李四      | 男     |
|  3 | 王五      | 男     |
+----+-----------+--------+
4 rows in set (0.00 sec)

新建一个表


mysql> create table product(
    -> id int primary key auto_increment,
    -> name varchar(45) not null,
    -> price float not null,
    -> qty int not null);
Query OK, 0 rows affected (0.03 sec)

查看表的内容


mysql> desc product;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| id    | int         | NO   | PRI | NULL    | auto_increment |
| name  | varchar(45) | NO   |     | NULL    |                |
| price | float       | NO   |     | NULL    |                |
| qty   | int         | NO   |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)

插入数据


mysql> insert into product (name,price,qty) values("香蕉",8.5,200) ;
Query OK, 1 row affected (0.01 sec)
 
mysql> insert into product (name,price,qty) values("苹果",12.5,400) ;
Query OK, 1 row affected (0.00 sec)
 
mysql> insert into product (name,price,qty) values("菠萝",12.4,70) ;
Query OK, 1 row affected (0.00 sec)
 
mysql> insert into product (name,price,qty) values("哈密瓜",18.3,400) ;
Query OK, 1 row affected (0.00 sec)

查看表


mysql> select * from product;
+----+-----------+-------+-----+
| id | name      | price | qty |
+----+-----------+-------+-----+
|  1 | 香蕉      |   8.5 | 200 |
|  2 | 苹果      |  12.5 | 400 |
|  3 | 菠萝      |  12.4 |  70 |
|  4 | 哈密瓜    |  18.3 | 400 |
+----+-----------+-------+-----+
4 rows in set (0.00 sec)

查看升序排列的qty


mysql> select * from product order by qty;
+----+-----------+-------+-----+
| id | name      | price | qty |
+----+-----------+-------+-----+
|  3 | 菠萝      |  12.4 |  70 |
|  1 | 香蕉      |   8.5 | 200 |
|  2 | 苹果      |  12.5 | 400 |
|  4 | 哈密瓜    |  18.3 | 400 |
+----+-----------+-------+-----+
4 rows in set (0.00 sec)

查看升序排列的价格


mysql> select * from product order by price;
+----+-----------+-------+-----+
| id | name      | price | qty |
+----+-----------+-------+-----+
|  1 | 香蕉      |   8.5 | 200 |
|  3 | 菠萝      |  12.4 |  70 |
|  2 | 苹果      |  12.5 | 400 |
|  4 | 哈密瓜    |  18.3 | 400 |
+----+-----------+-------+-----+
4 rows in set (0.00 sec)

先查看按照升序排列的qty，然后在这基础上在按照price的升序排列进行查看


mysql> select * from (select * from product order by qty ) as a order by a.price;
+----+-----------+-------+-----+
| id | name      | price | qty |
+----+-----------+-------+-----+
|  1 | 香蕉      |   8.5 | 200 |
|  3 | 菠萝      |  12.4 |  70 |
|  2 | 苹果      |  12.5 | 400 |
|  4 | 哈密瓜    |  18.3 | 400 |
+----+-----------+-------+-----+
4 rows in set (0.00 sec)

当使用聚合查询以后，不能使用where，如果要使用，添加having

聚合查询

练习


统计有多少男生和多少女生
 
mysql> select gender,count(gender) from student group by gender;
+--------+---------------+
| gender | count(gender) |
+--------+---------------+
| 男     |             3 |
| 女     |             1 |
+--------+---------------+
2 rows in set (0.00 sec)

写别名


mysql> select gender as 性别,count(gender) as 人数 from student group by gender;
+--------+--------+
| 性别   | 人数   |
+--------+--------+
| 男     |      3 |
| 女     |      1 |
+--------+--------+
2 rows in set (0.00 sec)

查看最大值、最小值、求和、求平均数


mysql> select  max(price) from product;
+------------+
| max(price) |
+------------+
|       18.3 |
+------------+
1 row in set (0.00 sec)
 
mysql> select min(price) from product;
+------------+
| min(price) |
+------------+
|        8.5 |
+------------+
1 row in set (0.00 sec)
 
mysql> select sum(price) from product;
+-------------------+
| sum(price)        |
+-------------------+
| 51.69999885559082 |
+-------------------+
1 row in set (0.00 sec)
 
mysql> select avg(price) from product;
+--------------------+
| avg(price)         |
+--------------------+
| 12.924999713897705 |
+--------------------+
1 row in set (0.00 sec)

日期


mysql> select year('1985-7-6') as birth;
+-------+
| birth |
+-------+
|  1985 |
+-------+
1 row in set (0.00 sec)
 
mysql> select month('1985-7-6') as birth;
+-------+
| birth |
+-------+
|     7 |
+-------+
1 row in set (0.00 sec)
 
mysql> select month('1985-7-6') as mon;
+------+
| mon  |
+------+
|    7 |
+------+
1 row in set (0.00 sec)

now-显示现在的时间


mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2024-08-07 15:30:36 |
+---------------------+
1 row in set (0.00 sec)
 
mysql> select year(now());
+-------------+
| year(now()) |
+-------------+
|        2024 |
+-------------+
1 row in set (0.00 sec)
 
mysql> select second(now());
+---------------+
| second(now()) |
+---------------+
|            59 |
+---------------+
1 row in set (0.00 sec)
 
mysql> insert into product (name,price,qty) values(now(),7.8,90);
Query OK, 1 row affected (0.02 sec)
 
mysql> select * from product;
+----+---------------------+-------+-----+
| id | name                | price | qty |
+----+---------------------+-------+-----+
|  1 | 香蕉                |   8.5 | 200 |
|  2 | 苹果                |  12.5 | 400 |
|  3 | 菠萝                |  12.4 |  70 |
|  4 | 哈密瓜              |  18.3 | 400 |
|  5 | 2024-08-07 15:32:48 |   7.8 |  90 |
+----+---------------------+-------+-----+
5 rows in set (0.00 sec)

分组查询


mysql> select gender,count(gender) from student group by gender;
+--------+---------------+
| gender | count(gender) |
+--------+---------------+
| 男     |             3 |
| 女     |             1 |
+--------+---------------+
2 rows in set (0.00 sec)
 
mysql> select gender as 性别,count(gender) as 人数 from student group by gender;
+--------+--------+
| 性别   | 人数   |
+--------+--------+
| 男     |      3 |
| 女     |      1 |
+--------+--------+
2 rows in set (0.00 sec)

子句查询


mysql> select sum(tt) from (select *,price*qty as tt  from product) as a;
+--------------------+
| sum(tt)            |
+--------------------+
| 14887.999668121338 |
+--------------------+
1 row in set (0.00 sec)

向下取整


mysql> select trim("a b");
+-------------+
| trim("a b") |
+-------------+
| a b         |
+-------------+
1 row in set (0.00 sec)
 
mysql> select floor(3.14);
+-------------+
| floor(3.14) |
+-------------+
|           3 |
+-------------+
1 row in set (0.00 sec)
 
mysql> select floor(-3.14);
+--------------+
| floor(-3.14) |
+--------------+
|           -4 |
+--------------+
1 row in set (0.00 sec)

向上取整


mysql> select ceiling(9.8);
+--------------+
| ceiling(9.8) |
+--------------+
|           10 |
+--------------+
1 row in set (0.00 sec)
 
mysql> select ceiling(9.3);
+--------------+
| ceiling(9.3) |
+--------------+
|           10 |
+--------------+
1 row in set (0.00 sec)

四舍五入


mysql> select round(9.3);
+------------+
| round(9.3) |
+------------+
|          9 |
+------------+
1 row in set (0.00 sec)
 
mysql> select round(9.5);
+------------+
| round(9.5) |
+------------+
|         10 |
+------------+
1 row in set (0.00 sec)

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