User and Access Control

User and Access control is a distingguished feature of TDengine enterprise edition. In this section, only the most fundamental functionalities of user and access control are demonstrated. To get the full knowledge of user and access control, please contact the TDengine team.

Create a User

CREATE USER user_name PASS 'password' [SYSINFO {1|0}];

This statement creates a user account.

The maximum length of user_name is 23 bytes.

The maximum length of password is 31 bytes. The password can include leters, digits, and special characters excluding single quotation marks, double quotation marks, backticks, backslashes, and spaces. The password cannot be empty.

SYSINFO indicates whether the user is allowed to view system information. 1 means allowed, 0 means not allowed. System information includes server configuration, dnode, vnode, storage. The default value is 1.

For example, we can create a user whose password is 123456 and is able to view system information.

taos> create user test pass '123456' sysinfo 1;
Query OK, 0 of 0 rows affected (0.001254s)

View Users

To show the users in the system, please use

SHOW USERS;

This is an example:

taos> show users;
           name           | super | enable | sysinfo |       create_time       |
================================================================================
 test                     |     0 |      1 |       1 | 2022-08-29 15:10:27.315 |
 root                     |     1 |      1 |       1 | 2022-08-29 15:03:34.710 |
Query OK, 2 rows in database (0.001657s)

Alternatively, you can get the user information by querying a built-in table, INFORMATION_SCHEMA.INS_USERS. For example:

taos> select * from information_schema.ins_users;
           name           | super | enable | sysinfo |       create_time       |
================================================================================
 test                     |     0 |      1 |       1 | 2022-08-29 15:10:27.315 |
 root                     |     1 |      1 |       1 | 2022-08-29 15:03:34.710 |
Query OK, 2 rows in database (0.001953s)

Delete a User

DROP USER user_name;

Modify User Information

ALTER USER user_name alter_user_clause
 
alter_user_clause: {
    PASS 'literal'
  | ENABLE value
  | SYSINFO value
}

• PASS: Modify the user password.
• ENABLE: Specify whether the user is enabled or disabled. 1 indicates enabled and 0 indicates disabled.
• SYSINFO: Specify whether the user can query system information. 1 indicates that the user can query system information and 0 indicates that the user cannot query system information.

For example, you can use below command to disable user test:

taos> alter user test enable 0;
Query OK, 0 of 0 rows affected (0.001160s)

Grant Permissions

Permission control is only available in TDengine Enterprise, please contact TDengine sales team.