mysql数据库的基本操作
首先我们要把mysql装好
mkdir chen/
mount.cifs //192.168.100.23/LNMP chen/
[root@localhost ~]# yum -y install \
gcc \
gcc-c++ \
ncurses \
ncurses-devel \
bison \
cmake
[root@localhost ~]# useradd -s /sbin/nologin mysql
[root@localhost ~]# cd chen/
[root@localhost chen]# ls
mysql-boost-5.7.20.tar.gz nginx-1.12.2.tar.gz php-7.1.20.tar.gz
nginx-1.12.0.tar.gz php-7.1.10.tar.bz2
[root@localhost chen]# tar zxvf mysql-boost-5.7.20.tar.gz -C /opt
[root@localhost chen]# cd /opt/
[root@localhost opt]# cd mysql-5.7.20/
cmake \
-DCMAKE_INSTALL_PREFIX=/usr/local/mysql \
-DMYSQL_UNIX_ADDR=/usr/local/mysql/mysql.sock \
-DSYSCONFDIR=/etc \
-DSYSTEMD_PID_DIR=/usr/local/mysql \
-DDEFAULT_CHARSET=utf8 \
-DDEFAULT_COLLATION=utf8_general_ci \
-DWITH_INNOBASE_STORAGE_ENGINE=1 \
-DWITH_ARCHIVE_STORAGE_ENGINE=1 \
-DWITH_BLACKHOLE_STORAGE_ENGINE=1 \
-DWITH_PERFSCHEMA_STORAGE_ENGINE=1 \
-DMYSQL_DATADIR=/usr/local/mysql/data \
-DWITH_BOOST=boost \
-DWITH_SYSTEMD=1
[root@localhost mysql-5.7.20]#make
[root@localhost mysql-5.7.20]#make install
[root@localhost mysql-5.7.20]#cd /usr/local/
[root@localhost local]# chown -R mysql:mysql mysql/
[root@localhost local]# cd /opt/mysql-5.7.20/
[root@localhost mysql-5.7.20]# vim /etc/my.cnf ##调整配置文件
[client] ##客户端
port = 3306
default-character-set=utf8
socket = /usr/local/mysql/mysql.sock
[mysql] ##客户端
port = 3306
default-character-set=utf8
socket = /usr/local/mysql/mysql.sock
[mysqld] ##服务器
user = mysql ##用户
basedir = /usr/local/mysql ##设置mysql的安装目录
datadir = /usr/local/mysql/data ##设置mysql数据库的数据的存放目录
port = 3306 ##设置3306端口
character_set_server=utf8 ##中文字符集
pid-file = /usr/local/mysql/mysqld.pid ##pid文件路径
socket = /usr/local/mysql/mysql.sock ##sock文件路径
server-id = 1 ##主从参数
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_AUTO_VALUE_ON_ZERO,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,PIPES_AS_CONCAT,ANSI_QUOTES
[root@localhost local]# echo 'PATH=/usr/local/mysql/bin:/usr/local/mysql/lib:$PATH' >> /etc/profile
#设置环境变量，使系统能识别bin和lib下的所有命令
[root@localhost local]# echo 'export PATH' >> /etc/profile
#全局变量
[root@localhost local]# source /etc/profile #重新启动系统环境变量
#初始化数据库
[root@localhost local]# cd /usr/local/mysql/
bin/mysqld \
--initialize-insecure \
--user=mysql \
--basedir=/usr/local/mysql \
--datadir=/usr/local/mysql/data
[root@localhost mysql]# cp usr/lib/systemd/system/mysqld.service /lib/systemd/system/
#把mysql启动脚本放到系统中可以systemctl可以管理
[root@localhost mysql]# systemctl start mysqld.service
[root@localhost ~]# systemctl enable mysqld #设置开启自启动mysql
Created symlink from /etc/systemd/system/multi-user.target.wants/mysqld.service to /usr/lib/systemd/system/mysqld.serv
[root@localhost mysql]# netstat -ntap | grep 3306
tcp6 0 0 :::3306 :::* LISTEN 73971/mysqld
#设置mysql密码
[root@localhost mysql]# mysqladmin -u root -p password '123123'#一开始是空的密码，可以设置abc123
Enter password:
New password:
Confirm new password:
Warning: Since password will be sent to server in plain text, use ssl connection to ensure password safety.
[root@localhost mysql]# mysql -u root -p
Enter password: 数据库基本操作命令
[root@localhost ~]# mysql -u root -p #进入数据库
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.7.20 Source distribution
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
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> use mysql #进入数据库
mysql> show tables; #查看数据库的所有表
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| engine_cost |
| event |
| func |
mysql> desc user; #显示数据表的结构
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Field | Type | Null | Key | Default | Extra |
+------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Host | char(60) | NO | PRI | | |
| User | char() | NO | PRI | | |
| Select_priv | enum('N','Y') | NO | | N | |
| Insert_priv | enum('N','Y') | NO | | N | |
| Update_priv | enum('N','Y') | NO | | N | |
| Delete_priv | enum('N','Y') 二分查找
以32为基准，比它大的放右边，比它小的放左边
数据库的四种操作语句
SQL语句概述
SQL语言
是Structured Query Language的缩写，即结构化查询语言
是关系型数据库的标准语言
用于维护管理数据库，如数据查询，数据更新，访问控制，对象管理等功能
> SQL分类
DDL：数据定义语言
DML：数据操纵语言
DQL：数据查询语言
DCL：数据控制语言
DDL语句操作
DDL语句用于创建数据库对象，如库，表，索引等
mysql> create databases test;
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 'databases test' at line 1
mysql> create database test;
Query OK, 1 row affected (0.00 sec)
mysql> use test;
Database changed
mysql>
mysql> create table info(
-> id int(3) not null,
-> name varchar(10) not null,
-> age int(5) not null,
-> score decimal default 0,
-> primary key (id));
Query OK, 0 rows affected (0.12 sec)
mysql> desc info;
+-------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------------+------+-----+---------+-------+
| id | int(3) | NO | PRI | NULL | |
| name | varchar(10) | NO | | NULL | |
| age | int(5) | NO | | NULL | |
| score | decimal(10,0) | YES | | 0 | |
+-------+---------------+------+-----+---------+-------+
4 rows in set (0.00 sec)DML语句操作
mysql> use test; #进入test数据库
Database changed
mysql>
mysql> create table info( #创建info数据表
-> id int(3) not null,
-> name varchar(10) not null,
-> age int(5) not null,
-> score decimal default 0,
-> primary key (id));
Query OK, 0 rows affected (0.12 sec)
mysql> desc info; #查看数据表结构
+-------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------------+------+-----+---------+-------+
| id | int(3) | NO | PRI | NULL | |
| name | varchar(10) | NO | | NULL | |
| age | int(5) | NO | | NULL | |
| score | decimal(10,0) | YES | | 0 | |
+-------+---------------+------+-----+---------+-------+
4 rows in set (0.00 sec)
mysql> insert into info values (1,'小陈',20,99); #插入数据
Query OK, 1 row affected (0.00 sec)
mysql> insert into info values (2,'小王',22,88);
Query OK, 1 row affected (0.00 sec)
mysql> insert into info values (3,'小高',25,77);
Query OK, 1 row affected (0.00 sec)
mysql> select * from info; #查看数据表当中的数据，这是DQL语句
+----+--------+-----+-------+
| id | name | age | score |
+----+--------+-----+-------+
| 1 | 小陈 | 20 | 99 |
| 2 | 小王 | 22 | 88 |
| 3 | 小高 | 25 | 77 |
+----+--------+-----+-------+
3 rows in set (0.01 sec)
mysql> update info set score='95' where id=1; #删除info表中的score列，来自主键索引id1
Query OK, 1 row affected (0.14 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from info;
+----+--------+-----+-------+
| id | name | age | score |
+----+--------+-----+-------+
| 1 | 小陈 | 20 | 95 |
| 2 | 小王 | 22 | 88 |
| 3 | 小高 | 25 | 77 |
+----+--------+-----+-------+
3 rows in set (0.00 sec)
mysql> delete from info where id =2 #删除id2这行数据
-> ;
Query OK, 1 row affected (0.01 sec)
mysql> select * from info;
+----+--------+-----+-------+
| id | name | age | score |
+----+--------+-----+-------+
| 1 | 小陈 | 20 | 95 |
| 3 | 小高 | 25 | 77 |
+----+--------+-----+-------+
2 rows in set (0.00 sec)
mysql> drop table info; #删除info数据表
Query OK, 0 rows affected (0.05 sec)
mysql> show tables; #查看数据表
Empty set (0.00 sec)
mysql> drop database test; #删除test数据库
Query OK, 0 rows affected (0.04 sec)
mysql> show databases; #查看数据库，当中没有test数据库了
+--------------------+
| Database |
+--------------------+
| information_schema |
| chen |
| mysql |
| performance_schema |
| school |
| sys |
+--------------------+
6 rows in set (0.00 sec)DQL语句操作
DQL是数据查询语句，只有一条：select
用于从数据表中查找符合条件的数据记录
查询时可不指定条件
mysql> select * from info;
+----+--------+-----+-------+
| id | name | age | score |
+----+--------+-----+-------+
| 1 | 小陈 | 20 | 95 |
| 3 | 小高 | 25 | 77 |
+----+--------+-----+-------+
2 rows in set (0.00 sec)
mysql> select name from info where name='小高'; ##查看指定条件
+--------+
| name |
+--------+
| 小高 |
+--------+
1 row in set (0.00 sec)DCL语言操作
设置用户权限（用户不存在时，则新建用户）
mysql> grant all privileges on *.* to 'root'@'%' identified by 'abc123';
Query OK, 0 rows affected, 1 warning (0.00 sec)
查看用户的权限
mysql> show grants for 'root'@'%';
+-------------------------------------------+
| Grants for root@% |
+-------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' |
+-------------------------------------------+
1 row in set (0.00 sec)
##撤销用户的权限
mysql> revoke all on *.* from 'root'@'%';
Query OK, 0 rows affected (0.00 sec)