mysql revoke privileges from user
To use REVOKE to recycle MySQL user permissions, you need to specify the permission type, database and user in the format. 1. Use REVOKE ALL PRIVILEGES, GRANT OPTION FROM 'Username'@'hostname'; 2. Use REVOKE ALL PRIVILEGES ON mydb. FROM 'Username'@'hostname'; 3. Use REVOKE ALL PRIVILEGES ON for global permissions. The permission type is ON .* FROM 'Username'@'hostname'; Note that it is recommended to refresh the permissions after execution. The permission scope must be consistent with the authorization time, and non-existent permissions cannot be recycled.
In MySQL, if you need to reclaim the permissions of a certain user, the REVOKE
statement is the command you want to use. It gives you the flexibility to remove one or more permissions without having to delete the entire user. Let me explain in detail how to operate it.

How to use REVOKE to recycle permissions
MySQL's REVOKE
command syntax structure is relatively fixed, and the basic format is as follows:
REVOKE Permission Type ON Database name. Table name FROM 'Username'@'Hostname';
For example, if you want to revoke the SELECT
permissions of the user 'testuser'@'localhost'
in the mydb
database to all tables, you can write it like this:

REVOKE SELECT ON mydb.* FROM 'testuser'@'localhost';
A few points to note:
- The permission types can be
SELECT
,INSERT
,UPDATE
, etc.; - Databases and tables can be represented by
*.*
for all tables in all databases; - The user must already exist, otherwise an error will be reported.
Common permission recovery scenarios
Recycle all permissions
If you want to reclaim all permissions of a user at one time, you can use:

REVOKE ALL PRIVILEGES, GRANT OPTION FROM 'Username'@'Hostname';
This command not only clears normal permissions, but also removes the user's ability to grant permissions to others (GRANT OPTION).
Recycle specific database permissions
For example, only reclaim all permissions of a user in the mydb
database:
REVOKE ALL PRIVILEGES ON mydb.* FROM 'testuser'@'localhost';
Recycle global permissions
If you gave the user global permissions (such as GRANT SELECT ON *.*
), and now you want to cancel, use:
REVOKE SELECT ON *.* FROM 'Username'@'Hostname';
Notes and FAQs
Remember to refresh permissions after executing REVOKE : Although manual refresh is not required in most cases, it is recommended to run it for the sake of safety:
FLUSH PRIVILEGES;
Non-existent permissions cannot be recycled : If you try to reclaim permissions that a user does not already have, MySQL will not report an error, but there will be no changes.
Root users should also be careful when operating : even for administrator accounts, don’t easily revoke their permissions, otherwise they may “lock out” themselves.
The permission range must match the settings during authorization : for example, when you authorized
mydb.mytable
, you must specify the same range when recycling, otherwise it may not work.
Basically that's it. Master the usage of REVOKE
and manage user permissions more refined and securely. It is not complicated but it is easy to ignore details, especially whether the permission objects match this. Many times the permissions are not recycled completely, because of this reason.
The above is the detailed content of mysql revoke privileges from user. For more information, please follow other related articles on the PHP Chinese website!

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To recycle MySQL user permissions using REVOKE, you need to specify the permission type, database, and user by format. 1. Use REVOKEALLPRIVILEGES, GRANTOPTIONFROM'username'@'hostname'; 2. Use REVOKEALLPRIVILEGESONmydb.FROM'username'@'hostname'; 3. Use REVOKEALLPRIVILEGESONmydb.FROM'username'@'hostname'; 3. Use REVOKE permission type ON.*FROM'username'@'hostname'; Note that after execution, it is recommended to refresh the permissions. The scope of the permissions must be consistent with the authorization time, and non-existent permissions cannot be recycled.

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