Arrays in PostgreSQL

-- Create table with arrays
CREATE TABLE products (
  id SERIAL PRIMARY KEY,
  name TEXT,
  tags TEXT[],           -- Array of text
  prices INTEGER[]       -- Array of integers
);

-- Insert arrays
INSERT INTO products (name, tags, prices) VALUES
  ('Laptop', ARRAY['electronics', 'computers'], ARRAY[999, 1299]),
  ('Book', '{"education", "programming"}', '{15, 20, 25}');

-- Query arrays
SELECT * FROM products 
WHERE 'electronics' = ANY(tags);     -- Contains value

SELECT * FROM products
WHERE tags @> ARRAY['computers'];    -- Contains all

-- DETAILED_TAB:
-- Array operations
SELECT 
  array_length(tags, 1),              -- Array length
  tags[1],                            -- First element (1-indexed!)
  array_append(tags, 'new'),          -- Add element
  array_remove(tags, 'old'),          -- Remove element
  unnest(tags)                        -- Expand to rows
FROM products;

-- Array aggregation
SELECT 
  category,
  array_agg(DISTINCT tag) AS all_tags
FROM product_tags
GROUP BY category;