Postgres and Open Source Experts

The JSON_ARRAY_ELEMENTS_TEXT() is a built-in JSON function that accepts a JSON array as an argument and expands its top-level elements into a set of text values.

To run PostgreSQL and pgAdmin using Docker, download Postgres and pgAdmin4 images from Docker Hub. Then, build and start the Postgres and pgAdmin4 containers.

The NTH_VALUE function in PostgreSQL is used to get the Nth_value from the table using the column and offset to set the value from the column.

To install PostgreSQL using Docker Compose, specify the desired services in compose file. Then, start the compose service to build and run Postgres container.

In PostgreSQL, the “CURRENT_USER”, “CURRENT_ROLE”, and “USER” methods are used to get the details of the current user.

In PostgreSQL, SETVAL() is one of the sequence functions that resets the current value of the selected sequence and retrieves the specified value.

To create a PostgreSQL database in Docker, use the “CREATE DATABASE <database-name>;” command. Then, create a new table in it and insert values in the table.

In PostgreSQL, several methods are used to check/find the hostnames and port numbers, such as the “\conninfo” command, the “pg_settings” view, etc.

To get the list of all stored procedures in a database, the “\df” command, “pg_proc” catalog, and “information_schema.routines” view are used in Postgres.

In PostgreSQL, a user-defined function can be created that accepts the table name and schema name as arguments.