MySQL基础命令总结

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所属分类：Database

MySQL版本：

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Server version: 5.7.21-20-29.26-log Percona XtraDB Cluster binary (GPL) 5.7.21-29.26, Revision 1702aea, wsrep_29.26

MySQL基础命令总结：

0：设置root密码

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$ /usr/local/mysql/bin/mysqladmin -u root password "admin"
> SET PASSWORD FOR root@'localhost' = PASSWORD('admin123');

1：修改用户密码

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$ /usr/local/mysql/bin/mysqladmin -uroot -padmin123 password admin
> SET PASSWORD = PASSWORD('admin');
> update mysql.user set authentication_string=password('admin') where user='root' and Host = 'localhost';    # > flush privileges;

2：删除多余用户

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> drop user ''@'localhost';
> delete from mysql.user where user='' and host='lamp';

3：建立数据库

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> create database abc;
> create database if not exists eof;
> create database t4x default character set gbk collate gbk_chinese_ci;
> create database t4x default character set utf8 collate utf8_general_ci;
> show charset;    #相关字符集

4：删除数据库

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> drop database abc;
> drop database if exists eof;

5：查看当前数据库

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> select database();

6：建立用户且授权

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> CREATE USER 'jeffrey'@'localhost' IDENTIFIED BY 'password';    #建立用户jeffrey,localhost
> GRANT ALL ON d01.* TO 'jeffrey'@'localhost';    #给新建立的用户jiffrey设置在数据库d01拥有所有权限
> GRANT ALL PRIVILEGES ON d01.* to 'abc'@'localhost' identified by 'password';     #建立用户abc，且授权abc拥有d01的所有权限
> show grants for 'jeffrey'@'localhost';    #查看jeffrey在本地的权限

7：回收用户权限

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> REVOKE INSERT ON d01.* FROM 'jeffrey'@'localhost';
> show grants for 'jeffrey'@'localhost';
GRANT SELECT, UPDATE, DELETE, CREATE, DROP, REFERENCES, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, EVENT, TRIGGER ON `d01`.* TO 'jeffrey'@'localhost'

8：建数据表

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> create table stu( id int(4) not null, name char(20) not null, age tinyint(2) NOT NULL default '0', dept varchar(16) default NULL );

9：查看表结构

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> desc stu;
> show columns from stu;

10：查看建表语句

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> show create table student\G
(root@localhost) [d01]> show create table student\G
*************************** 1. row ***************************
       Table: student
Create Table: CREATE TABLE `student` (
  `id` int(4) NOT NULL AUTO_INCREMENT,
  `name` char(20) NOT NULL,
  `age` tinyint(2) NOT NULL DEFAULT '0',
  `dept` varchar(16) DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `index_name` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

11：删除表

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> drop table stu;

12：删除主键

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(root@localhost) [d01]> desc student;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| id    | int(4)      | NO   | PRI | NULL    | auto_increment |
| name  | char(20)    | NO   | MUL | NULL    |                |
| age   | tinyint(2)  | NO   |     | 0       |                |
| dept  | varchar(16) | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+
(root@localhost) [d01]> alter table student change id id int;    #有自增必须删除自增
(root@localhost) [d01]> desc student;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | NO   | PRI | NULL    |       |
| name  | char(20)    | NO   | MUL | NULL    |       |
| age   | tinyint(2)  | NO   |     | 0       |       |
| dept  | varchar(16) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
(root@localhost) [d01]> alter table student drop primary key;    #删除主键      
(root@localhost) [d01]> desc student;                        
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | NO   |     | NULL    |       |
| name  | char(20)    | NO   | MUL | NULL    |       |
| age   | tinyint(2)  | NO   |     | 0       |       |
| dept  | varchar(16) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
4 rows in set (0.00 sec)

13：增加主键

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(root@localhost) [d01]> alter table student change id id int primary key auto_increment;
Query OK, 0 rows affected (0.02 sec)
Records: 0  Duplicates: 0  Warnings: 0
 
(root@localhost) [d01]> desc student;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| id    | int(11)     | NO   | PRI | NULL    | auto_increment |
| name  | char(20)    | NO   | MUL | NULL    |                |
| age   | tinyint(2)  | NO   |     | 0       |                |
| dept  | varchar(16) | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+
(root@localhost) [d01]> alter table student change id id int primary key;              
Query OK, 0 rows affected (0.28 sec)
Records: 0  Duplicates: 0  Warnings: 0
 
(root@localhost) [d01]> desc student;                        
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | NO   | PRI | NULL    |       |
| name  | char(20)    | NO   | MUL | NULL    |       |
| age   | tinyint(2)  | NO   |     | 0       |       |
| dept  | varchar(16) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
(root@localhost) [d01]> alter table student drop index index_name;  
(root@localhost) [d01]> alter table student add index index_name(name);
(root@localhost) [d01]> desc student;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | NO   | PRI | NULL    |       |
| name  | char(20)    | NO   |     | NULL    |       |
| age   | tinyint(2)  | NO   |     | 0       |       |
| dept  | varchar(16) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
4 rows in set (0.02 sec)
 
(root@localhost) [d01]> create index index_name on student(name(11));
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0
 
(root@localhost) [d01]> desc student;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | NO   | PRI | NULL    |       |
| name  | char(20)    | NO   | MUL | NULL    |       |
| age   | tinyint(2)  | NO   |     | 0       |       |
| dept  | varchar(16) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
(root@localhost) [d01]> show create table student\G
*************************** 1. row ***************************
       Table: student
Create Table: CREATE TABLE `student` (
  `id` int(11) NOT NULL,
  `name` char(20) NOT NULL,
  `age` tinyint(2) NOT NULL DEFAULT '0',
  `dept` varchar(16) DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `index_name` (`name`(11))
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
(root@localhost) [d01]> show index from student\G
*************************** 1. row ***************************
        Table: student
   Non_unique: 0
     Key_name: PRIMARY
Seq_in_index: 1
  Column_name: id
    Collation: A
  Cardinality: 0
     Sub_part: NULL
       Packed: NULL
         Null:
   Index_type: BTREE
      Comment:
Index_comment:
*************************** 2. row ***************************
        Table: student
   Non_unique: 1
     Key_name: index_name
Seq_in_index: 1
  Column_name: name
    Collation: A
  Cardinality: 0
     Sub_part: 11
       Packed: NULL
         Null:
   Index_type: BTREE
      Comment:
Index_comment:
(root@localhost) [d01]> create index ind_name_dept on student(name,dept);
(root@localhost) [d01]> drop index ind_name_dept on student;
(root@localhost) [d01]> create index ind_name_dept on student(name(11),dept(10));
(root@localhost) [d01]> create unique index uni_ind_dept on student(dept);
Query OK, 0 rows affected (0.03 sec)
Records: 0  Duplicates: 0  Warnings: 0
 
(root@localhost) [d01]> desc student;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | NO   | PRI | NULL    |       |
| name  | char(20)    | NO   | MUL | NULL    |       |
| age   | tinyint(2)  | NO   |     | 0       |       |
| dept  | varchar(16) | YES  | UNI | NULL    |       |
+-------+-------------+------+-----+---------+-------+
 
 
(root@localhost) [d01]> CREATE TABLE employee (id int(10),name char(20),phone int(12));
(root@localhost) [d01]> INSERT INTO employee(id,name,phone) VALUES(01,'Tom',110110110);
ERROR 1105 (HY000): Percona-XtraDB-Cluster prohibits use of DML command on a table (d01.employee) without an explicit primary key with pxc_strict_mode = ENFORCING or MASTER
(root@localhost) [d01]> alter table employee change id id int primary key;
 
(root@localhost) [d01]> select * from stu;                                        
+----+------+-----+------+
| id | name | age | dept |
+----+------+-----+------+
|  1 | abc  |  12 | eee  |
|  2 | tom  |  13 | fff  |
+----+------+-----+------+
2 rows in set (0.00 sec)
(root@localhost) [d01]> delete from stu;
Query OK, 2 rows affected (0.03 sec)
 
(root@localhost) [d01]> select * from stu;
Empty set (0.00 sec)
 
(root@localhost) [d01]> show create table stu\G
*************************** 1. row ***************************
       Table: stu
Create Table: CREATE TABLE `stu` (
  `id` int(11) NOT NULL,
  `name` char(20) NOT NULL,
  `age` tinyint(2) NOT NULL DEFAULT '0',
  `dept` varchar(16) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)