HSTORE

HSTORE is a SQL data type in the PostgreSQL Specific category. PostgreSQL key-value store within a column. Stores sets of key:value pairs in a single value. The syntax is column HSTORE. It returns hstore value. A typical example: CREATE EXTENSION IF NOT EXISTS hstore; CREATE TABLE products (id INT, attributes HSTORE); INSERT INTO products VALUES (1, 'color => "red", size => "M", weight => "1.5"'); SELECT attributes->'color' FROM products WHERE id = 1; -- 'red' SELECT * FROM products WHERE attributes ? 'color'; -- Has color key SELECT * FROM products WHERE attributes @> 'color => "red"'; A close relative is SERIAL, which postgreSQL auto-increment type. Creates an INTEGER column with a sequence. Equivalent to AUTO_INCREMENT in MySQL. A close relative is RETURNING, which postgreSQL extension that returns values from INSERT/UPDATE/DELETE statements (like OUTPUT in SQL Server). A close relative is ARRAY, which postgreSQL supports array columns and array operations. Can be multi-dimensional.