To list all installed extensions in PostgreSQL, you can query the pg_extension system catalog table as shown below: SELECT extname FROM pg_extension; This query retrieves the names of all installed extensions in your PostgreSQL database.

To remove special characters from a string in PostgreSQL, you can use a combination of string manipulation functions like REGEXP_REPLACE and regular expressions to target and replace those characters. Here’s an example of how you can remove special characters from a string: Suppose you have a table named “my_table” with a column “my_column” containing strings…

To revoke superuser privileges from a user in PostgreSQL, you’ll need to connect to the PostgreSQL database server as a superuser, typically the “postgres” user. Here are the steps to revoke superuser privileges: Log in as the PostgreSQL superuser: Open a terminal and log in as the PostgreSQL superuser, usually named “postgres.” You can do…

Superusers have full control over the database server and can perform any administrative task. Granting superuser privileges to a user should be done carefully, as it comes with significant power and responsibility. To grant superuser privileges to a user in PostgreSQL, follow these steps: Option 1: During PostgreSQL Installation Option 2: Using an Existing Superuser…

To rename a column in PostgreSQL, you can use the ALTER TABLE statement with the RENAME COLUMN clause. Below is the basic syntax for renaming a column in PostgreSQL: ALTER TABLE table_name RENAME COLUMN old_column_name TO new_column_name; where table_name is the name of the table containing the column you want to rename, old_column_name is the…

To list all databases in PostgreSQL, you can use the following SQL command: SELECT datname FROM pg_database; Above query will display a list of database names currently available on the server. You should have the necessary permissions to list databases on the PostgreSQL server. If you encounter permission issues, make sure you are logged in…

To change the owner of all tables within a specific schema in PostgreSQL, you can use a combination of SQL queries to generate and execute the necessary ALTER TABLE statements. Run the following SQL query to generate a list of ALTER TABLE statements for all tables in the schema you want to change the owner…

To get the name of the current database in PostgreSQL, you can use the following SQL query: SELECT current_database(); When you execute this query, it will return the name of the database that you are currently connected to. For example, if you are connected to a database named “my_database,” executing the query will return “my_database”…

To move a table from one schema to another in PostgreSQL database, you can use the ALTER TABLE statement with the SET SCHEMA clause. Here’s the basic syntax: ALTER TABLE old_schema.table_name SET SCHEMA new_schema; where old_schema is the name of the current schema where the table resides. table_name is the name of the table you…

You can retrieve the username of the currently logged-in user using the current_user function. SELECT current_user; When you execute this SQL query, it will return the username of the currently logged-in user as a text value. You can use this information in your SQL queries or as part of your application to determine the current…