老男孩mysql练习题自我学习

  1. 登陆数据库

    [email protected] ~]#mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.5.38 MySQL Community Server (GPL) by Remi

Copyright (c) 2000, 2014, 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.

[[email protected] ~]#mysql -u root -p123456

Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
  2. 查看数据库版本及当前登陆用户是什么 
    mysql> select version();
+-----------+
| version() |
+-----------+
| 5.5.38    |
+-----------+
1 row in set (0.00 sec)

mysql> select user();
+----------------+
| user()         |
+----------------+
| [email protected] |
+----------------+
1 row in set (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| activiti_test      |
| monitor            |
| mysql              |
| osa                |
| osa_guard          |
| sms                |
| test               |
| yandi_monitor      |
+--------------------+
  3. 创建GBK字符集的数据库inline，并查看已建库的完整语句。 
    mysql> create database inline default charset gbk;
Query OK, 1 row affected (0.01 sec)

mysql> show create database inline;
+----------+----------------------------------------------------------------+
| Database | Create Database                                                |
+----------+----------------------------------------------------------------+
| inline   | CREATE DATABASE `inline` /*!40100 DEFAULT CHARACTER SET gbk */ |
+----------+----------------------------------------------------------------+
1 row in set (0.00 sec)
  4. 创建用户inline，使之可以管理数据库inline； 
    mysql> grant all on inline.* to [email protected] identified by ‘inline‘;
Query OK, 0 rows affected (0.00 sec)
  5. 查看创建用户inline拥有哪些权限 
    mysql> show grants for [email protected];
+---------------------------------------------------------------------------------------------------------------+
| Grants for [email protected]                                                                                   |
+---------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO ‘inline‘@‘localhost‘ IDENTIFIED BY PASSWORD ‘*49129FD3218473FFCCE66D799E25FB6AFD6E0A73‘ |
| GRANT ALL PRIVILEGES ON `inline`.* TO ‘inline‘@‘localhost‘                                                    |
+---------------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
  6. 进入inline数据库： 
    mysql> use inline
Database changed
  7. 创建一innodb引擎字符集为GBK表test，字段id和name varchar（16），查看建表结构及SQL语句 
    mysql> create table test(
    -> id int,
    -> name varchar(16))
    -> engine innodb default charset gbk;
Query OK, 0 rows affected (0.01 sec)

mysql> show create table test;
+-------+--------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table                                                                                                             |
+-------+--------------------------------------------------------------------------------------------------------------------------+
| test  | CREATE TABLE `test` (
  `id` int(11) DEFAULT NULL,
  `name` varchar(16) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=gbk |
+-------+--------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> show variables like ‘char%‘;
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | gbk                        |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | latin1                     |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

mysql> desc test
    -> ;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | YES  |     | NULL    |       |
| name  | varchar(16) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.01 sec)
  8. 插入一条数据： 
    mysql> insert into test value(0,‘inlineuser‘);
Query OK, 1 row affected (0.00 sec)
  9. 批量插入数据，要求中文不能为乱码 
    mysql> insert into test value(1,‘inlineuser‘),(2,‘中文‘);
Query OK, 2 rows affected (0.02 sec)
Records: 2  Duplicates: 0  Warnings: 0
  10. 查询插入的所有记录 
    mysql> ?select * from test;
+------+------------+
| id   | name       |
+------+------------+
|    0 | inlineuser |
|    1 | inlineuser |
|    2 | 中文       |
+------+------------+
3 rows in set (0.00 sec)
  11. 查询id大于1的记录 
    mysql> select * from test where id>1;
+------+--------+
| id   | name   |
+------+--------+
|    2 | 中文   |
+------+--------+
1 row in set (0.00 sec)
  12. 更新id=1的记录 
    ysql> update test set name=‘inuser‘ where id=1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from test;
+------+--------------+
| id   | name         |
+------+--------------+
|    0 | inlineuser   |
|    1 | inuser |
|    2 | 中文         |
+------+--------------+
3 rows in set (0.00 sec)
  13. 在字段name前插入age字段，类型int(4) 
    mysql> alter table test add age int(4) after id;
Query OK, 3 rows affected (0.01 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> desc test;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | YES  |     | NULL    |       |
| age   | int(4)      | YES  |     | NULL    |       |
| name  | varchar(16) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)

mysql>
  14. 备份inline数据库及mysql数据库 
    [[email protected] ~]#mysqldump -B inline,mysql >/tmp/backup.sqlmysqldump: Got error: 1049: Unknown database ‘inline,mysql‘ when selecting the database
[[email protected] ~]#mysqldump -B inline mysql >/tmp/backup.sql
-- Warning: Skipping the data of table mysql.event. Specify the --events option explicitly.
[[email protected] ~]#mysqldump --events -B inline mysql >/tmp/backup.sql
  15. 删除表中的所有数据。 
    mysql> delete from test;
Query OK, 3 rows affected (0.02 sec)
  16. 恢复数据 
    [[email protected] ~]#vim /tmp/backup.sql
[[email protected] ~]#mysql </tmp/backup.sql
[[email protected] ~]#mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 5.5.38 MySQL Community Server (GPL) by Remi

Copyright (c) 2000, 2014, 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 inline
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 * from test;
+------+------+--------------+
| id   | age  | name         |
+------+------+--------------+
|    0 | NULL | inlineuser   |
|    1 | NULL | inlineunuser |
|    2 | NULL | 中文         |
+------+------+--------------+
3 rows in set (0.00 sec)

mysql> desc test
    -> ;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | YES  |     | NULL    |       |
| age   | int(4)      | YES  |     | NULL    |       |
| name  | varchar(16) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)
  17. 将inline数据库改为utf8编码 
    [[email protected] ~]#sed -i "s/gbk/utf8/g" /tmp/backup.sql
[[email protected] ~]#vim /tmp/backup.sql

[[email protected] ~]#mysql < /tmp/backup.sql
[[email protected] ~]#mysql inline
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 12
Server version: 5.5.38 MySQL Community Server (GPL) by Remi

Copyright (c) 2000, 2014, 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> select * from test;
+------+------+--------------+
| id   | age  | name         |
+------+------+--------------+
|    0 | NULL | inlineuser   |
|    1 | NULL | inlineunuser |
|    2 | NULL | 中文         |
+------+------+--------------+
3 rows in set (0.00 sec)

mysql>
  18. 忘记mysql root用户密码 
    [[email protected] ~]#/usr/bin/mysqld_safe --skip-grant-tables &
mysql> select host,user,password from mysql.user where user=‘root‘;
+-----------------------+------+-------------------------------------------+
| host                  | user | password                                  |
+-----------------------+------+-------------------------------------------+
| localhost             | root | *509910ED20429303306B7D5FA9215C7EC9E54B68 |
| localhost.localdomain | root |                                           |
| 127.0.0.1             | root |                                           |
+-----------------------+------+-------------------------------------------+
3 rows in set (0.00 sec)

mysql> update mysql.user set password=password(123456) where user=‘root‘ and host=‘localhost‘;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> exit
Bye
[[email protected] ~]#/etc/init.d/mysqld stop
150920 09:37:22 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
Stopping mysqld:                                           [  OK  ]
[1]+  Done                    /usr/bin/mysqld_safe --skip-grant-tables
[[email protected] ~]#/etc/init.d/mysqld start
Starting mysqld:                                           [  OK  ]
[[email protected] ~]#mysql -uroot -p123456
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.5.38 MySQL Community Server (GPL) by Remi

Copyright (c) 2000, 2014, 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>
  19. 在把id列设置为主键，在Name字段上创建普通索引 
    mysql> alter table test add primary key idx_p(id);
Query OK, 3 rows affected (0.02 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> desc test
    -> ;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(11)     | NO   | PRI | 0       |       |
| age   | int(4)      | YES  |     | NULL    |       |
| name  | varchar(16) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)

mysql> alter table test add index idx_name(name);
Query OK, 0 rows affected (0.02 sec)
Records: 0  Duplicates: 0  Warnings: 0
  20. 在字段name后插入手机号码字段（moble），类型char（11） 
    mysql> alter table test add mobile char(11);
Query OK, 3 rows affected (0.02 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> desc test
    -> ;
+--------+-------------+------+-----+---------+-------+
| Field  | Type        | Null | Key | Default | Extra |
+--------+-------------+------+-----+---------+-------+
| id     | int(11)     | NO   | PRI | 0       |       |
| age    | int(4)      | YES  |     | NULL    |       |
| name   | varchar(16) | YES  | MUL | NULL    |       |
| mobile | char(11)    | YES  |     | NULL    |       |
+--------+-------------+------+-----+---------+-------+
4 rows in set (0.00 sec)

mysql> select * from test;
+----+------+--------------+--------+
| id | age  | name         | mobile |
+----+------+--------------+--------+
|  0 | NULL | inlineuser   | NULL   |
|  1 | NULL | inlineunuser | NULL   |
|  2 | NULL | 中文         | NULL   |
+----+------+--------------+--------+
3 rows in set (0.00 sec)

mysql> insert into test values(3,5,‘foson‘,‘13455556666‘),(4,5,‘foson‘,‘13577889966‘);
Query OK, 2 rows affected (0.01 sec)
Records: 2  Duplicates: 0  Warnings: 0

mysql> select * from test;
+----+------+--------------+-------------+
| id | age  | name         | mobile      |
+----+------+--------------+-------------+
|  0 | NULL | inlineuser   | NULL        |
|  1 | NULL | inlineuser | NULL        |
|  2 | NULL | 中文         | NULL        |
|  3 |    5 | foson     | 13455556666 |
|  4 |    5 | foson      | 13577889966 |
+----+------+--------------+-------------+
5 rows in set (0.00 sec)
  21. 在手机字段上对前8个字符创建普通索引 
    mysql> alter table test add index idx_m (mobile(8));
Query OK, 0 rows affected (0.02 sec)
Records: 0  Duplicates: 0  Warnings: 0
mysql> show index from test;
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| test  |          0 | PRIMARY  |            1 | id          | A         |           5 |     NULL | NULL   |      | BTREE      |         |               |
| test  |          1 | idx_name |            1 | name        | A         |           5 |     NULL | NULL   | YES  | BTREE      |         |               |
| test  |          1 | idx_m    |            1 | mobile      | A         |           5 |        8 | NULL   | YES  | BTREE      |         |               |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
3 rows in set (0.00 sec)

mysql> show index from test\G;
*************************** 1. row ***************************
        Table: test
   Non_unique: 0
     Key_name: PRIMARY
 Seq_in_index: 1
  Column_name: id
    Collation: A
  Cardinality: 5
     Sub_part: NULL
       Packed: NULL
         Null:
   Index_type: BTREE
      Comment:
Index_comment:
*************************** 2. row ***************************
        Table: test
   Non_unique: 1
     Key_name: idx_name
 Seq_in_index: 1
  Column_name: name
    Collation: A
  Cardinality: 5
     Sub_part: NULL
       Packed: NULL
         Null: YES
   Index_type: BTREE
      Comment:
Index_comment:
*************************** 3. row ***************************
        Table: test
   Non_unique: 1
     Key_name: idx_m
 Seq_in_index: 1
  Column_name: mobile
    Collation: A
  Cardinality: 5
     Sub_part: 8
       Packed: NULL
         Null: YES
   Index_type: BTREE
      Comment:
Index_comment:
3 rows in set (0.00 sec)

ERROR:
No query specified
  22. 删除name mobile列的索引 
    mysql> alter table test drop index idx_name;
Query OK, 0 rows affected (0.00 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> alter table test drop index idx_m;
Query OK, 0 rows affected (0.00 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> show index from test\G;
*************************** 1. row ***************************
        Table: test
   Non_unique: 0
     Key_name: PRIMARY
 Seq_in_index: 1
  Column_name: id
    Collation: A
  Cardinality: 5
     Sub_part: NULL
       Packed: NULL
         Null:
   Index_type: BTREE
      Comment:
Index_comment:
1 row in set (0.00 sec)

ERROR:
No query specified
  23. 对name列的钱6个字符以及手机列的钱8个字符组建联合索引 
    mysql> alter table test add index idx_n_m (name(6),mobile(8));
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> show index from test\G;
*************************** 1. row ***************************
        Table: test
   Non_unique: 0
     Key_name: PRIMARY
 Seq_in_index: 1
  Column_name: id
    Collation: A
  Cardinality: 5
     Sub_part: NULL
       Packed: NULL
         Null:
   Index_type: BTREE
      Comment:
Index_comment:
*************************** 2. row ***************************
        Table: test
   Non_unique: 1
     Key_name: idx_n_m
 Seq_in_index: 1
  Column_name: name
    Collation: A
  Cardinality: 5
     Sub_part: 6
       Packed: NULL
         Null: YES
   Index_type: BTREE
      Comment:
Index_comment:
*************************** 3. row ***************************
        Table: test
   Non_unique: 1
     Key_name: idx_n_m
 Seq_in_index: 2
  Column_name: mobile
    Collation: A
  Cardinality: 5
     Sub_part: 8
       Packed: NULL
         Null: YES
   Index_type: BTREE
      Comment:
Index_comment:
3 rows in set (0.00 sec)

ERROR:
No query specified
  24. 有索引及没有索引执行计划的不同 
    mysql> select * from test where name=‘foson‘ and mobile like ‘135%‘;
+----+------+---------+-------------+
| id | age  | name    | mobile      |
+----+------+---------+-------------+
|  4 |    5 | foson | 13577889966 |
+----+------+---------+-------------+
1 row in set (0.00 sec)

mysql> explain select * from test where name=‘foson‘ and mobile like ‘135%‘;
+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+
| id | select_type | table | type  | possible_keys | key     | key_len | ref  | rows | Extra       |
+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+
|  1 | SIMPLE      | test  | range | idx_n_m       | idx_n_m | 46      | NULL |    1 | Using where |
+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+
1 row in set (0.01 sec)

mysql> alter table test drop index idx_n_m;
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> explain select * from test where name=‘foson‘ and mobile like ‘135%‘;
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra       |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
|  1 | SIMPLE      | test  | ALL  | NULL          | NULL | NULL    | NULL |    5 | Using where |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
1 row in set (0.00 sec)

mysql> 

mysql> alter table test add index idx_n_m (name(6),mobile(8));
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> explain select * from test where  mobile like ‘135%‘;
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra       |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
|  1 | SIMPLE      | test  | ALL  | NULL          | NULL | NULL    | NULL |    5 | Using where |
+----+-------------+-------+------+---------------+------+---------+------+------+-------------+
1 row in set (0.00 sec)

mysql> explain select * from test where name=‘foson‘ and mobile like ‘135%‘;
+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+
| id | select_type | table | type  | possible_keys | key     | key_len | ref  | rows | Extra       |
+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+
|  1 | SIMPLE      | test  | range | idx_n_m       | idx_n_m | 46      | NULL |    1 | Using where |
+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+
1 row in set (0.00 sec)

mysql> explain select * from test where name=‘foson‘;
+----+-------------+-------+------+---------------+---------+---------+-------+------+-------------+
| id | select_type | table | type | possible_keys | key     | key_len | ref   | rows | Extra       |
+----+-------------+-------+------+---------------+---------+---------+-------+------+-------------+
|  1 | SIMPLE      | test  | ref  | idx_n_m       | idx_n_m | 21      | const |    2 | Using where |
+----+-------------+-------+------+---------------+---------+---------+-------+------+-------------+
1 row in set (0.00 sec)

mysql>
时间： 2024-10-28 14:28:35

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