mysql> grant all on *.* to developer@localhost;
ERROR 1410 (42000): You are not allowed to create a user with GRANT
mysql> grant all on *.* to Tom@localhost;
Query OK, 0 rows affected (0.01 sec)
mysql> select user,host from user;
+------------------+-----------+
| user | host |
+------------------+-----------+
| Tom | localhost |
| developer | localhost |
| mysql.infoschema | localhost |
| mysql.session | localhost |
| mysql.sys | localhost |
| root | localhost |
+------------------+-----------+
6 rows in set (0.00 sec)
mysql> select * from user where user = "Tom";
+-----------+------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+------------------------+----------+------------------------+--------------------------+----------------------------+---------------+-------------+-----------------+----------------------+-----------------------+------------------------------------------------------------------------+------------------+-----------------------+-------------------+----------------+------------------+----------------+------------------------+---------------------+--------------------------+-----------------+
| Host | User | Select_priv | Insert_priv | Update_priv | Delete_priv | Create_priv | Drop_priv | Reload_priv | Shutdown_priv | Process_priv | File_priv | Grant_priv | References_priv | Index_priv | Alter_priv | Show_db_priv | Super_priv | Create_tmp_table_priv | Lock_tables_priv | Execute_priv | Repl_slave_priv | Repl_client_priv | Create_view_priv | Show_view_priv | Create_routine_priv | Alter_routine_priv | Create_user_priv | Event_priv | Trigger_priv | Create_tablespace_priv | ssl_type | ssl_cipher | x509_issuer | x509_subject | max_questions | max_updates | max_connections | max_user_connections | plugin | authentication_string | password_expired | password_last_changed | password_lifetime | account_locked | Create_role_priv | Drop_role_priv | Password_reuse_history | Password_reuse_time | Password_require_current | User_attributes |
+-----------+------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+------------------------+----------+------------------------+--------------------------+----------------------------+---------------+-------------+-----------------+----------------------+-----------------------+------------------------------------------------------------------------+------------------+-----------------------+-------------------+----------------+------------------+----------------+------------------------+---------------------+--------------------------+-----------------+
| localhost | Tom | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | N | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | | NULL | NULL | NULL | 0 | 0 | 0 | 0 | caching_sha2_password | $A$005$u!`!4TVC7F<L/v+E2n9ydD.t.nTBGt80zCpn3lBi05xkBOXbfk.RruKKW0 | N | 2021-06-25 13:40:24 | NULL | N | Y | Y | NULL | NULL | NULL | NULL |
+-----------+------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+------------------------+----------+------------------------+--------------------------+----------------------------+---------------+-------------+-----------------+----------------------+-----------------------+------------------------------------------------------------------------+------------------+-----------------------+-------------------+----------------+------------------+----------------+------------------------+---------------------+--------------------------+-----------------+
1 row in set (0.00 sec)
mysql> select * from user where user = "developer";
+-----------+-----------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+------------------------+----------+------------------------+--------------------------+----------------------------+---------------+-------------+-----------------+----------------------+-----------------------+------------------------------------------+------------------+-----------------------+-------------------+----------------+------------------+----------------+------------------------+---------------------+--------------------------+-----------------+
| Host | User | Select_priv | Insert_priv | Update_priv | Delete_priv | Create_priv | Drop_priv | Reload_priv | Shutdown_priv | Process_priv | File_priv | Grant_priv | References_priv | Index_priv | Alter_priv | Show_db_priv | Super_priv | Create_tmp_table_priv | Lock_tables_priv | Execute_priv | Repl_slave_priv | Repl_client_priv | Create_view_priv | Show_view_priv | Create_routine_priv | Alter_routine_priv | Create_user_priv | Event_priv | Trigger_priv | Create_tablespace_priv | ssl_type | ssl_cipher | x509_issuer | x509_subject | max_questions | max_updates | max_connections | max_user_connections | plugin | authentication_string | password_expired | password_last_changed | password_lifetime | account_locked | Create_role_priv | Drop_role_priv | Password_reuse_history | Password_reuse_time | Password_require_current | User_attributes |
+-----------+-----------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+------------------------+----------+------------------------+--------------------------+----------------------------+---------------+-------------+-----------------+----------------------+-----------------------+------------------------------------------+------------------+-----------------------+-------------------+----------------+------------------+----------------+------------------------+---------------------+--------------------------+-----------------+
| localhost | developer | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | | NULL | NULL | NULL | 0 | 0 | 0 | 0 | caching_sha2_password | 7c4a8d09ca3762af61e59520943dc26494f8941b | N | NULL | NULL | N | N | N | NULL | NULL | NULL | NULL |
+-----------+-----------+-------------+-------------+-------------+-------------+-------------+-----------+-------------+---------------+--------------+-----------+------------+-----------------+------------+------------+--------------+------------+-----------------------+------------------+--------------+-----------------+------------------+------------------+----------------+---------------------+--------------------+------------------+------------+--------------+------------------------+----------+------------------------+--------------------------+----------------------------+---------------+-------------+-----------------+----------------------+-----------------------+------------------------------------------+------------------+-----------------------+-------------------+----------------+------------------+----------------+------------------------+---------------------+--------------------------+-----------------+
1 row in set (0.00 sec)Tom和developer分别是两个用户，但是为啥developer赋予权限会报错：You are not allowed to create a user with GRANT，而Tom不会？
根据你提供的信息，我们可以看到在赋予权限时出现了错误，其中Tom和developer是两个不同的用户，而developer在设置权限时出现了错误。这是因为你现在使用的用户并没有具有创建用户的权限，所以你无法使用CREATE USER语句来创建新的用户。相反，你可能需要使用GRANT命令来向现有的用户授予权限。在这种情况下，你需要使用GRANT命令来授予developer创建新用户的权限，然后再尝试创建新用户。如下所示：
GRANT CREATE USER ON *.* TO developer@localhost;
然后再执行以下命令：
CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password';
由于Tom已经具备所需的权限，可以成功地创建一个新的用户。因此，你必须在developer用户上授予适当的权限才能执行相同的操作。