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mysql学习(linux系统)

mysql学习(linux系统)

作者: 伤了谁疼111 | 来源:发表于2018-12-15 20:01 被阅读0次

    一、安装

    [root@xue ~]# yum -y install mariadb-server mariadb
    

    二、启动

    [root@xue ~]# systemctl start mariadb
    [root@xue ~]# systemctl enable mariadb
    Created symlink from /etc/systemd/system/multi-user.target.wants/mariadb.service to /usr/lib/systemd/system/mariadb.service.
    

    三、设置初始密码

    [root@xue ~]# mysql_secure_installation
    [root@xue ~]# ps -ef | grep mysqld
    mysql    31338     1  0 03:04 ?        00:00:00 /bin/sh /usr/bin/mysqld_safe --basedir=/usr
    mysql    31495 31338  0 03:04 ?        00:00:00 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --log-error=/var/log/mariadb/mariadb.log --pid-file=/var/run/mariadb/mariadb.pid --socket=/var/lib/mysql/mysql.sock
    root     31597 28727  0 03:06 pts/0    00:00:00 grep --color=auto mysqld
    [root@xue ~]# mysqladmin -uroot -p create RUNOOB
    Enter password: 
    [root@xue ~]# mysqladmin -uroot -p drop RUNOOB
    Enter password: 
    Dropping the database is potentially a very bad thing to do.
    Any data stored in the database will be destroyed.
    
    Do you really want to drop the 'RUNOOB' database [y/N] Y
    Database "RUNOOB" dropped
    

    四、进入数据库

    [root@xue ~]# mysql -uroot -p
    
    

    五、创建数据库

    MariaDB [(none)]> create database pap;
    Query OK, 1 row affected (0.00 sec)
    

    六、创建数据表

    MariaDB [pap]> create table class (stu int,name varchar(20),agr int,area varchar(20));
    Query OK, 0 rows affected (0.20 sec)
    
    MariaDB [pap]> create table score (stu int,name varchar(20),ke varchar(10),fen int);
    Query OK, 0 rows affected (0.10 sec)
    
    MariaDB [php]> create table msg(id int,title varchar(60),name varchar(10),content varchar(1000))engine=innodb default charset=utf8;
    Query OK, 0 rows affected (0.10 sec)
    

    七、插入数据

    MariaDB [pap]> insert into msg(id,title,name,content) values (1,'初来乍到','张三','分解到家');
    Query OK, 1 row affected (0.09 sec)
    
    MariaDB [pap]> insert into msg(id,title,name,content) values (2,'又来了','李四','见覅off');
    Query OK, 1 row affected (0.03 sec)
    
    MariaDB [pap]> insert into msg
        -> values
        -> (3,'冯家湾','几覅哦','几覅欧文'),
        -> (4,'范围房','房价跟','飞机我啊'),
        -> (5,'房价而','佛教房','飞机瓦尔');
    Query OK, 3 rows affected (0.13 sec)
    Records: 3  Duplicates: 0  Warnings: 0
    

    八、修改数据

    MariaDB [pap]> update msg set id=2,content='房间爱我' where name='李四';
    Query OK, 1 row affected (0.11 sec)
    Rows matched: 1  Changed: 1  Warnings: 0
    
    MariaDB [pap]> insert into msg values ();
    Query OK, 1 row affected, 3 warnings (0.70 sec)
    

    九、删除某行数据

    MariaDB [pap]> delete from msg where id=2;
    Query OK, 1 row affected (0.12 sec)
    

    十、查找数据

    MariaDB [pap]> select id,title from msg;
    +------+--------------+
    | id   | title        |
    +------+--------------+
    |    1 | 初来乍到     |
    |    3 | 冯家湾       |
    |    4 | 范围房       |
    |    5 | 房价而       |
    | NULL |              |
    +------+--------------+
    5 rows in set (0.00 sec)
    
    MariaDB [pap]> select name,content from msg where id>2;
    +-----------+--------------+
    | name      | content      |
    +-----------+--------------+
    | 几覅哦    | 几覅欧文     |
    | 房价跟    | 飞机我啊     |
    | 佛教房    | 飞机瓦尔     |
    +-----------+--------------+
    3 rows in set (0.00 sec)
    

    十一、删除表

    MariaDB [pap]> drop table class;
    Query OK, 0 rows affected (0.11 sec)
    
    MariaDB [pap]> create table class( id int primary key auto_increment,name varchar(10),age tinyint)charset utf8;
    Query OK, 0 rows affected (0.14 sec)
    
    MariaDB [pap]> insert into class (name,age) values ('zhangsan',25);
    Query OK, 1 row affected (0.03 sec)
    
    MariaDB [pap]> insert into class (name,age) values ('zhangsan',127);
    Query OK, 1 row affected (0.10 sec)
    
    MariaDB [pap]> insert into class (name,age) values ('zhangsan',-128);
    Query OK, 1 row affected (0.11 sec)
    

    十二、插入行

    MariaDB [pap]> alter table class add age2 tinyint unsigned;
    Query OK, 3 rows affected (0.12 sec)               
    Records: 3  Duplicates: 0  Warnings: 0
    
    MariaDB [pap]> insert into class(name,age,age2) values ('lisi',25,0);
    Query OK, 1 row affected (0.04 sec)
    
    MariaDB [pap]> alter table class add age3 tinyint(1);
    Query OK, 4 rows affected (0.21 sec)               
    Records: 4  Duplicates: 0  Warnings: 0
    

    浮点型

    MariaDB [pap]> create table goods(name varchar(10) not null default '',price float(6,2) not null default 0.00) charset=utf8;
    Query OK, 0 rows affected (0.14 sec)
    
    MariaDB [pap]> insert into goods(name,price) values ('跑步机',688.896);
    Query OK, 1 row affected (0.10 sec)
    
    MariaDB [pap]> alter table goods add bigprice float(9,2) not null default 0.0;
    Query OK, 1 row affected (0.14 sec)                
    Records: 1  Duplicates: 0  Warnings: 0
    
    MariaDB [pap]> alter table goods add deciprice decimal(9,2) not null default 0.0;
    Query OK, 1 row affected (0.07 sec)                
    Records: 1  Duplicates: 0  Warnings: 0
    
    MariaDB [pap]> insert into goods(name,bigprice,deciprice) values ('',1234567.23,1234567.23);
    Query OK, 1 row affected (0.26 sec)
    
    MariaDB [pap]> select * from goods;
    +-----------+--------+------------+------------+
    | name      | price  | bigprice   | deciprice  |
    +-----------+--------+------------+------------+
    | 跑步机    | 688.90 |       0.00 |       0.00 |
    |           |   0.00 | 1234567.25 | 1234567.23 |
    +-----------+--------+------------+------------+
    2 rows in set (0.00 sec)
    
    MariaDB [pap]> create table stu(name char(8) not null default '',waihao varchar(10) not null default '')charset utf8;
    Query OK, 0 rows affected (0.11 sec)
    
    
    

    year类型

    MariaDB [pap]> create table y(ya year(4));
    Query OK, 0 rows affected (0.12 sec)
    
    MariaDB [pap]> insert into y values ('1901');
    Query OK, 1 row affected (0.33 sec)
    
    MariaDB [pap]> insert into y values ('2200');
    Query OK, 1 row affected, 1 warning (0.00 sec)
    
    MariaDB [pap]> insert into y values ('97');
    Query OK, 1 row affected (0.09 sec)
    
    MariaDB [pap]> insert into y values ('12');
    Query OK, 1 row affected (0.44 sec)
    

    date类型

    MariaDB [pap]> create table d(title varchar(30),dt date)charset utf8;
    Query OK, 0 rows affected (0.11 sec)
    
    MariaDB [pap]> insert into d values ('开国大典','1994-10-01');
    Query OK, 1 row affected (0.07 sec)
    
    MariaDB [pap]> insert into d values ('世界末日','2012-02-30');
    Query OK, 1 row affected, 1 warning (0.26 sec)
    

    time类型

    MariaDB [pap]> create table t(tm time);
    Query OK, 0 rows affected (0.43 sec)
    
    MariaDB [pap]> insert into t values ('13:34:56');
    Query OK, 1 row affected (0.36 sec)
    
    MariaDB [pap]> insert into t values ('13:60:00');
    Query OK, 1 row affected, 1 warning (0.36 sec)
    

    日期时间类型

    MariaDB [pap]> create table user(name varchar(20) not null default '',regtime datetime not null default '1000-01-01 00:00:00')charset utf8;
    Query OK, 0 rows affected (0.21 sec)
    
    MariaDB [pap]> insert into user(name) values ('张三');
    Query OK, 1 row affected (0.04 sec)
    
    MariaDB [pap]> insert into user values ('李四','2012-02-22 14:28:36');
    Query OK, 1 row affected (0.33 sec)
    
    MariaDB [pap]> create table teacher(name varchar(20),gender tinyint)engine=innodb default charset utf8;
    Query OK, 0 rows affected (0.36 sec)
    
    MariaDB [pap]> insert into teacher values ('张',1);
    Query OK, 1 row affected (0.10 sec)
    
    MariaDB [pap]> create table t2(gender enum('男','女'))charset utf8;
    Query OK, 0 rows affected (0.36 sec)
    
    MariaDB [pap]> insert into t2 values ('男');
    Query OK, 1 row affected (0.34 sec)
    
    MariaDB [pap]> insert into t2 values ('女');
    Query OK, 1 row affected (0.10 sec)
    
    MariaDB [pap]> insert into t2 values ('春哥');
    Query OK, 1 row affected, 1 warning (0.16 sec)
    

    综合练习

    创建数据表

    MariaDB [pap]> 
    MariaDB [pap]> create table wl163(
        -> id int primary key auto_increment,
        -> name char(3) not null default '',
        -> age tinyint unsigned not null default 0,
        -> email varchar(30) not null default '',
        -> tel char(11) not null default '',
        -> salary decimal(7,2) not null default '1900.79',
        -> riqi date not null default '2018-12-15'
        -> )charset=utf8;
    Query OK, 0 rows affected (0.13 sec)
    

    插入数据

    MariaDB [pap]> insert into wl163
        -> (name,age,email,tel,riqi)
        -> values
        -> ('陈心宇',21,'chenxinyu@yz.com','18912499740','2016-09-10');
    Query OK, 1 row affected (0.10 sec)
    
    MariaDB [pap]> insert into wl163
        -> values
        -> (3,'段宗?',21,'duanzonghe@ah.com','18951312252',1234.56,'2016-09-10');
    Query OK, 1 row affected (0.10 sec)
    
    MariaDB [pap]> insert into wl163
        -> (name,age,email)
        -> values
        -> ('薛怀',21,'xuehuai@ha.com'),
        -> ('杨其龙',21,'yangqilong@sh.com'),
        -> ('张迁',21,'zhangqian@sy.com'),
        -> ('王欣',21,'wangxin@ah.com');
    Query OK, 4 rows affected (0.11 sec)
    Records: 4  Duplicates: 0  Warnings: 0
    

    修改数据

    MariaDB [pap]> update wl163
        -> set
        -> tel='15161737044',
        -> salary=3999.99
        -> where id=4;
    

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