oracle user query permissions

Oracle is an enterprise-level database management system. It is the preferred database for many enterprises and organizations for data storage and management. For users in the database, query permissions are very important because users need to query what they need. Have a full understanding and mastery of the data used. This article will introduce how to query Oracle database user permissions.

1. Overview of Oracle database user permissions

In the Oracle database, all users have permissions, including connecting to the database, creating tables and views, inserting, deleting and modifying data, etc. In order to control user access to the database, Oracle divides permissions into three categories.

1. System-level permissions: System permissions allow users to access and manage all data and objects on the database instance, including creating and deleting users, modifying instance parameters, etc. Only specific users or privileged users can have this permission.

2. Object-level permissions: Object permissions allow users to access and manage specific objects (such as tables, views, stored procedures, etc.), including SELECT, INSERT, UPDATE, DELETE, etc. Object permissions can be granted or revoked by the object's owner or a privileged user.

3. Row-level permissions: Row-level permissions allow users to access only some rows or columns in a table. For each table, row-level permissions can be granted or revoked by the table owner or a privileged user.

2. Different methods of querying Oracle database user permissions

In order to query Oracle database user permissions, you can use views, user fields or functions in the Enterprise Manager.

1. Using views

Oracle provides some specific views to query user permissions. The following are some commonly used views:

•dba_sys_privs: Query the system-level permissions of all users.

•dba_tab_privs: Query the permissions of all objects, such as tables, views and stored procedures.

•dba_role_privs: Query the role permissions of all users.

•dba_col_privs: Query the permissions of columns in the table.

For example, if you want to query the object permissions of user "scott", you can execute the following command:

SELECT * FROM dba_tab_privs WHERE grantee='SCOTT';

This will Returns a list of objects owned by this user.

2. Using User Fields

Each user in Oracle database has an associated user field that contains details about user permissions and other related information. If you want to query the permissions of user "scott", you can execute the following command:

SELECT * FROM user_tab_privs WHERE grantee='SCOTT';

This will return a list of objects owned by this user.

3. Use Enterprise Manager

Oracle's Enterprise Manager is a graphical tool that allows administrators to manage and monitor Oracle databases. If you use Enterprise Manager, you can easily find the permissions of your database users. After opening Enterprise Manager, select the desired user and click on the "Object Privileges" tab. This returns the permissions the user has on the object.

3. Summary

In Oracle database, it is very important to understand database user permissions, because it can help understand what data and objects each user can access and manage. Methods for querying Oracle database user permissions include using views, user fields, or Enterprise Manager. We can choose the most suitable method according to our needs.

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