MySQL 8.4 Reference Manual Including MySQL NDB Cluster 8.4
The USER_ATTRIBUTES table provides
information about user comments and user attributes. It takes its
values from the mysql.user system table.
The USER_ATTRIBUTES table has these
columns:
USER
The user name portion of the account to which the
ATTRIBUTE column value applies.
HOST
The host name portion of the account to which the
ATTRIBUTE column value applies.
ATTRIBUTE
The user comment, user attribute, or both belonging to the
account specified by the USER and
HOST columns. The value is in JSON object
notation. Attributes are shown exactly as set using
CREATE
USER and
ALTER
USER statements with ATTRIBUTE or
COMMENT options. A comment is shown as a
key-value pair having comment as the key.
For additional information and examples, see
CREATE USER Comment and Attribute Options.
USER_ATTRIBUTES is a nonstandard
INFORMATION_SCHEMA table.
To obtain only the user comment for a given user as an unquoted string, you can employ a query such as this one:
mysql>SELECT ATTRIBUTE->>"$.comment" AS Comment->FROM INFORMATION_SCHEMA.USER_ATTRIBUTES->WHERE USER='bill' AND HOST='localhost';+-----------+ | Comment | +-----------+ | A comment | +-----------+
Similarly, you can obtain the unquoted value for a given user attribute using its key.
USER_ATTRIBUTES contents are
accessible as follows:
All rows are accessible if:
The current thread is a replica thread.
The access control system has not been initialized
(for example, the server was started with the
--skip-grant-tables
option).
The currently authenticated account has the
UPDATE or
SELECT privilege for
the mysql.user system table.
The currently authenticated account has the
CREATE USER and
SYSTEM_USER privileges.
Otherwise, the currently authenticated account can see the
row for that account. Additionally, if the account has the
CREATE USER privilege but
not the SYSTEM_USER
privilege, it can see rows for all other accounts that do
not have the SYSTEM_USER
privilege.
For more information about specifying account comments and attributes, see Section 15.7.1.3, “CREATE USER Statement”.