How to implement the statement to view user role members in MySQL?

How to implement the statement to view user role members in MySQL?

MySQL, as a commonly used relational database management system, provides rich functions to manage user roles. In practical applications, we often need to view the roles to which the user belongs and the members of the roles. This article will introduce how to implement the statement to view user role members in MySQL and give specific code examples.

The function of viewing user role members can be implemented in MySQL through the following steps:

1. Create users and roles
   First, we need to create users and roles for subsequent operations. You can create a user and a role in MySQL using the following code:

CREATE USER 'user1'@'localhost' IDENTIFIED BY 'password1';
CREATE ROLE 'role1';

2. Add user to role
   Next, we need to add the user to the role, use the following code Add user 'user1' to role 'role1':

GRANT role1 TO user1;

3. View user role members
   Once the user and role are created and added, we can use the following statement to View the roles and role members to which the user belongs:

SELECT * FROM mysql.user_roles WHERE user = 'user1';

In the above statement, 'mysql.user_roles' is a MySQL system table used to store the relationship between users and roles. By specifying 'user1' as a filter condition, we can view the roles to which user 'user1' belongs.

4. Interpretation of results
   After executing the above query statement, we can get a result set containing the columns "user" and "role". The column "user" represents the name of the user, and the column "role" represents the role to which the user belongs.

If we want to view the members of the role, we can use the following statement:

SELECT * FROM mysql.role_edges WHERE FROM_HOST = 'user1' AND FROM_USER = '';

In the above statement, 'mysql.role_edges' is another system table used to store roles and roles member relations. By specifying 'FROM_HOST' as the user name and 'FROM_USER' as the empty string filter condition, we can view the members of the role to which the user belongs.

It should be noted that the names of users and roles, and the names of system tables may differ depending on the MySQL version and configuration. Please adjust according to the actual situation.

Summary:
This article introduces how to view the statements of user role members in MySQL and gives specific code examples. By creating users and roles, adding the user to the role, and then querying the system tables, we can easily see what roles the user belongs to and who is a member of the role. This is very helpful for managing and controlling access to the database. Hope this article can help you with your need to view user role members in MySQL.

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