Postgres and Open Source Experts

To include multiple PostgreSQL databases in Docker container, continuously run the “CREATE DATABASE <database-name>” command with different database names.

In PostgreSQL, the “table inheritance” allows us to create a hierarchy of tables, where one table(child) can inherit the structure and properties of another (parent) table.

In PostgreSQL, the “UNIQUE” keyword is used with the CREATE TABLE or ALTER TABLE commands to add a unique constraint on single/multiple columns of a new or an already existing Postgres table.

The DENSE_RANK() function assigns a rank to each row of a partition based on the specified sorting order. It starts ranking from 1 for the first row and increases the rank for each subsequent row.

PostgreSQL supports various commands to create a database from the command line, including “createdb” and “CREATE DATABASE”.

The NTILE function is used to divide the rows of the table into groups provided by the users in the argument of the function called buckets in PostgreSQL.

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

To execute PostgreSQL Query in Docker container, run Postgres container and interact with it. Then, connect to database server and execute PostgreSQL commands.

In PostgreSQL, the UPPER_INC() function accepts a range or multi-range as an argument and checks if the upper bound of the specified range is included in the range or not.

In PostgreSQL, a built-in function named “JSON_ARRAY_LENGTH()” is used to determine the length of a JSON array.