PostgreSQL – How to Drop A User

To add a NOT NULL constraint to 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 SET NOT NULL; where table_name is the name of the table you want to modify, and column_name is the…

To drop (delete) a table in PostgreSQL, you can use the DROP TABLE statement. Here’s the basic syntax: DROP TABLE table_name; where table_name is the name of the table you want to drop. Here’s an example of how to use this syntax to drop a table named my_table: DROP TABLE my_table; Be very cautious when…

To change a user’s password in PostgreSQL, you can use the ALTER USER statement. Here’s how you can change a user’s password: Connect to PostgreSQL: You need to connect to your PostgreSQL server using a user account with superuser or administrative privileges, as only superusers can change the passwords of other users. Change the Password:To…

To get the size of a specific table in PostgreSQL, you can use the pg_total_relation_size function. This function returns the total size of a table in bytes, including the main data file, indexes, and associated objects. Below is the syntax: SELECT pg_size_pretty(pg_total_relation_size(‘your_table_name’)); where ‘your_table_name’ with the name of the table you want to get the…

You can convert a timestamp to a date in PostgreSQL using the DATE function. If you have a timestamp column named “order_ts” in a table called “orders,” you can use the following query to convert the timestamp to a date: SELECT DATE(order_ts) FROM orders; This will return a result set where each row contains the…

You can convert a date to a string using the TO_CHAR function in PostgreSQL database. TO_CHAR function allows you to format the date as a string with a specific format. Here’s how you can do it: SELECT TO_CHAR(your_date_column, ‘YYYY-MM-DD’) AS date_string FROM your_table; In the above syntax, The format string ‘YYYY-MM-DD’ specifies the desired format…