PostgreSQL – How to List All Databases

To list all columns of a table in PostgreSQL, you can use the \d command within the psql command-line tool or use SQL queries to retrieve column information from the system catalog. Here are a couple of methods to accomplish this: Method 1: Using psql Open a terminal and start the psql command-line tool by…

You can rename a constraint in PostgreSQL database using the ALTER TABLE statement. Renaming a constraint is useful when you want to give it a more meaningful or descriptive name or if you need to change its name for any other reason. Here’s the basic syntax for renaming a constraint: ALTER TABLE table_name RENAME CONSTRAINT…

You can rename a sequence using the ALTER SEQUENCE statement with the RENAME TO clause in PostgreSQL database. Here’s the basic syntax for renaming a sequence: ALTER SEQUENCE old_sequence_name RENAME TO new_sequence_name; where old_sequence_name is the current name of the sequence you want to rename, and new_sequence_name is the new name you want to assign…

To drop a schema in PostgreSQL, you can use the DROP SCHEMA statement. Here’s the basic syntax for dropping a schema: DROP SCHEMA schema_name [ CASCADE ]; where schema_name is the name of the schema you want to drop. The optional CASCADE keyword is used to automatically drop all objects (tables, views, functions, etc.) within…

To create a new user in PostgreSQL, you can use the CREATE USER SQL command. Below is the basic syntax: CREATE USER username [WITH PASSWORD ‘password’]; where username is the desired username for the new user, and [WITH PASSWORD ‘password’] is optional. If you include the password, the user will be created with that password….

To drop a NOT NULL constraint from an existing column in a PostgreSQL table, you can use the ALTER TABLE statement with the ALTER COLUMN clause. Here’s the basic syntax: ALTER TABLE table_name ALTER COLUMN column_name DROP NOT NULL; where table_name is the name of the table containing the column and column_name is the name…