Ch 2 · PostgreSQL Data Types · PostgreSQL
Topic 2 of 3 in PostgreSQL — Complete Tutorial (Beginner) — 4 lessons.
Advanced Data Types
Explore PostgreSQL unique data types: arrays, JSON, UUID, and custom types. PostgreSQL goes well beyond standard SQL here. An array column holds several values at once, JSONB stores JSON in a fast, searchable binary form, UUID gives IDs that are unique everywhere, and CREATE TYPE lets you define an enum with a fixed list of allowed values. Together they let one table store flexible data neatly.
Advanced Data Types in Code
These PostgreSQL-only examples show four special types in action. A TEXT[] column stores tags, searched with ANY. A JSONB column stores event data, where -> returns JSON and ->> returns plain text. gen_random_uuid(), built into PostgreSQL 13 and later, generates UUID keys with no extension needed, and CREATE TYPE ... AS ENUM limits a column to set values. Notice the ::jsonb cast, which marks the text as JSON explicitly.
Practice: Advanced Data Types
Practise PostgreSQL's special types by building a small table of your own with a tags array and a JSONB metadata column. You will insert a few records, then query them by an array element and by a JSON field. A correct answer uses ANY to search the array and picks the right arrow operator depending on whether you want JSON or text back.
Solution & Challenge: Advanced Data Types
Compare your table and queries with the worked solution, which stores tags in an array and view counts in JSONB. The challenge then asks you to design a product catalogue where different products can have different attributes. A good answer uses JSONB for those flexible attributes, a text array for tags and a UUID for the public-facing ID, and queries all of them.