1.查詢所有存在的資料庫

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
4 rows in set (0.13 sec)

2.使用一個數據庫

mysql> use test
Database changed

3.查詢一個數據庫內的所有表

mysql> show tables
    -> ;
+---------------------------+
| Tables_in_mysql           |
+---------------------------+
| columns_priv              |
| db                        |
| event                     |
| func                      |
| general_log               |
| help_category             |
| help_keyword              |
| help_relation             |
| help_topic                |
| innodb_index_stats        |
| innodb_table_stats        |
| ndb_binlog_index          |
| plugin                    |
| proc                      |
| procs_priv                |
| proxies_priv              |
| servers                   |
| slave_master_info         |
| slave_relay_log_info      |
| slave_worker_info         |
| slow_log                  |
| tables_priv               |
| time_zone                 |
| time_zone_leap_second     |
| time_zone_name            |
| time_zone_transition      |
| time_zone_transition_type |
| user                      |
+---------------------------+
28 rows in set (0.00 sec)
 

4.新增使用者user01，密碼123456的使用者

mysql> GRANT USAGE ON *.* TO 'user01'@'localhost' IDENTIFIED BY '123456' WITH GRANT OPTION;
Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

5.查詢所有使用者

mysql> select host, user, password from user where user = 'root';
+----------------------------------+------+-------------------------------------------+
| host                             | user | password                                  |
+----------------------------------+------+-------------------------------------------+
| localhost                        | root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
| 1dot1dot1dot1.cloudflare-dns.com | root |                                           |
| 127.0.0.1                        | root |                                           |
| ::1                              | root |                                           |
+----------------------------------+------+-------------------------------------------+
4 rows in set (0.00 sec)

mysql> select host, user, password from user where user = 'user01';
+-----------+--------+-------------------------------------------+
| host      | user   | password                                  |
+-----------+--------+-------------------------------------------+
| localhost | user01 | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+-----------+--------+-------------------------------------------+
1 row in set (0.00 sec)

 

可以看到user01使用者被建立了，同時密碼被加密了，mysql8以後的版本加密使用MD5()，而不是password()

6.展示表的列

mysql> show columns in db;
+-----------------------+---------------+------+-----+---------+-------+
| Field                 | Type          | Null | Key | Default | Extra |
+-----------------------+---------------+------+-----+---------+-------+
| Host                  | char(60)      | NO   | PRI |         |       |
| Db                    | char(64)      | NO   | PRI |         |       |
| User                  | char(16)      | 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') | NO   |     | N       |       |
| Create_priv           | enum('N','Y') | NO   |     | N       |       |
| Drop_priv             | enum('N','Y') | NO   |     | N       |       |
| Grant_priv            | enum('N','Y') | NO   |     | N       |       |
| References_priv       | enum('N','Y') | NO   |     | N       |       |
| Index_priv            | enum('N','Y') | NO   |     | N       |       |
| Alter_priv            | enum('N','Y') | NO   |     | N       |       |
| Create_tmp_table_priv | enum('N','Y') | NO   |     | N       |       |
| Lock_tables_priv      | enum('N','Y') | NO   |     | N       |       |
| Create_view_priv      | enum('N','Y') | NO   |     | N       |       |
| Show_view_priv        | enum('N','Y') | NO   |     | N       |       |
| Create_routine_priv   | enum('N','Y') | NO   |     | N       |       |
| Alter_routine_priv    | enum('N','Y') | NO   |     | N       |       |
| Execute_priv          | enum('N','Y') | NO   |     | N       |       |
| Event_priv            | enum('N','Y') | NO   |     | N       |       |
| Trigger_priv          | enum('N','Y') | NO   |     | N       |       |
+-----------------------+---------------+------+-----+---------+-------+
22 rows in set (0.00 sec)

7.展示表的所有索引

mysql> show index from db;
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| db    |          0 | PRIMARY  |            1 | Host        | A         |        NULL |     NULL | NULL   |      | BTREE      |         |               |
| db    |          0 | PRIMARY  |            2 | Db          | A         |        NULL |     NULL | NULL   |      | BTREE      |         |               |
| db    |          0 | PRIMARY  |            3 | User        | A         |           2 |     NULL | NULL   |      | BTREE      |         |               |
| db    |          1 | User     |            1 | User        | A         |           1 |     NULL | NULL   |      | BTREE      |         |               |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
4 rows in set (0.00 sec)