对miek这个账号localhost 授予了所有库，所表的select权限
mysql> grant select on *.* to 'mike'@'localhost';
Query OK, 0 rows affected (0.00 sec)
mysql> exit
Bye
[root@mysql ~]# mysql -umike -p123
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.6.36 Source distributionCopyright (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>
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| company |
| db1 |
| db2 |
| db3 |
| db4 |
| db5 |
| db6 |
| mysql |
| performance_schema |
| test |
| test2 |
| test_1 |
+--------------------+
13 rows in set (0.04 sec)mysql> use db1;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -ADatabase changed
mysql> show tables;
+---------------+
| Tables_in_db1 |
+---------------+
| innodb__t_t1 |
| innodb__t_t2 |
| innodb__t_t3 |
| innodb__t_t4 |
| t1 |
| t3 |
+---------------+
6 rows in set (0.00 sec)mysql> select * from t1;
+------+------+--------+------+
| id | name | sex | age |
+------+------+--------+------+
| 1 | mike | male | 15 |
| 2 | alex | female | 16 |
| 3 | NULL | NULL | NULL |
| 4 | NULL | NULL | NULL |
+------+------+--------+------+
4 rows in set (0.01 sec)mysql> desc t1;
+-------+-----------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-----------------------+------+-----+---------+-------+
| id | int(11) | YES | | NULL | |
| name | varchar(50) | YES | | NULL | |
| sex | enum('male','female') | YES | | NULL | |
| age | int(4) | YES | | NULL | |
+-------+-----------------------+------+-----+---------+-------+
4 rows in set (0.00 sec)mysql> insert into t1 values(5,'jack','male',50);
ERROR 1142 (42000): INSERT command denied to user 'mike'@'localhost' for table 't1'
没有插入记录权限，只有select权限
