Contents

• pg_sample_ext
  • Installation
  • Usage
    • square
    • Composite Type (person_type):
    • Enumerated Type (status_type):
    • Domain Type (positive_integer):
    • Custom Operator (@*):
    • Contributing
  • License

pg_sample_ext

pg_sample_ext is a PostgreSQL extension that provides a sample function to demonstrate extending PostgreSQL's functionality.

Installation

1. Make sure you have PostgreSQL installed and running.

2. Clone or download the repository pg_sample_ext to your local machine.

3. Change to the extension directory:

$ cd pg_sample_ext

1. Build and install the extension:

   $ make $ make install

2. Enable the extension: 

CREATE EXTENSION pg_sample_ext;

Usage

Once the pg_sample_ext extension is installed and upgraded to version 1.0.1, you can use the included functions and new features in your SQL queries.

square

The square function calculates the square of a number.

SELECT square(5); -- Returns 25

Composite Type (person_type):

• The extension now includes a composite type named person_type that represents a person's name and age. This allows for more structured data storage and retrieval.
• Insert a row with a value from the composite type

INSERT INTO my_table (person) VALUES (('John Doe', 30));

Enumerated Type (status_type):

• A new enumerated type called status_type is introduced, which provides a predefined set of values for representing different statuses. This enhances data integrity and enables more meaningful data classification.
• Insert a row with a value from the enumerated type

INSERT INTO status_table (status) VALUES ('active');

Domain Type (positive_integer):

• The extension now includes a domain type called positive_integer, which is a specialized data type that represents positive integers. This allows for better constraint enforcement and data validation.
• Insert a row, ensuring the quantity is a positive integer

INSERT INTO quant_table (quantity) VALUES (10);

Custom Operator (@*):

• The extension introduces a custom operator @* that performs a custom operation, such as multiplication, on values of a specific type. -- It multiplies two values of type my_type and returns a value of the same type.

SELECT ROW(2)::my_type @* ROW(3)::my_type AS result;

Contributing

Contributions are welcome! If you find any issues or have suggestions for improvements, please open an issue or submit a pull request on the GitHub repository pg_sample_ext.

License

This project is licensed under the PostgreSQL License.