PostgreSQL – How to view the Session User

ByAdmin

You can use the session_user function to retrieve the name of the user that established the database session.

Here’s how you can use the session_user function in SQL queries:

SELECT session_user;

When you execute this SQL query, it will return the name of the user that established the session. It could be same as currently logged-in user if no other role has been set.

For example, if you are logged in as the user “john,” executing the query will return:

session_user 
------------- 
john 
(1 row)

You can use the session_user function in various scenarios, such as when you need to record the user who made a change to the database or when you want to control access to certain data or functions based on the user’s identity.

Keep in mind that session_user returns the username as a text string, and it is read-only. It cannot be used to change the user’s session state.

Similar Posts

PostgreSQL – How to Create a Materialized View

ByAdmin

Creating a materialized view in PostgreSQL involves using the CREATE MATERIALIZED VIEW statement. A materialized view is a precomputed and stored view of the data from one or more tables. Using materialized views can improve query performance by reducing the need to repeatedly compute the same complex queries. Here’s the basic syntax for creating a…

PostgreSQL – How to Convert Timestamp to String

ByAdmin

You can convert a timestamp to a string in PostgreSQL database using the TO_CHAR function, which allows you to format the timestamp as a string with a specific format. Here’s how you can do it: SELECT TO_CHAR(your_timestamp_column, ‘YYYY-MM-DD HH24:MI:SS’) AS timestamp_string FROM your_table; where The format string ‘YYYY-MM-DD HH24:MI:SS’ specifies the desired format for the…

PostgreSQL – How to List Tables Used by A View

ByAdmin

To list the tables used by a view in PostgreSQL, you can query the system catalog to inspect the view’s underlying SQL query. PostgreSQL stores view definitions in the pg_views system catalog table. Here’s how you can retrieve the tables used by a specific view: SELECT table_name FROM information_schema.tables WHERE table_schema = ‘public’ AND table_name…

PostgreSQL – How to Delete Duplicate Rows in PostgreSQL Database

ByAdmin

To delete duplicate rows in PostgreSQL using a self-join, you can use the DELETE statement along with a self-join condition. Here’s the syntax: DELETE FROM your_table a USING your_table b WHERE a.column_name = b.column_name AND a.ctid < b.ctid; where your_table is the actual name of your table, and column_name is the column that you want…

PostgreSQL – How to Disable(Lock) a User

ByAdmin

You can disable a user account in PostgreSQL database by revoking their login privileges. Disabling a user prevents them from connecting to the PostgreSQL database server. Here’s the basic syntax to revoke login privileges from a user globally: ALTER USER username NOLOGIN; Where username is the name of the user you want to lock/disable. By…