Lesson 3 — Filtering with WHERE

Filtering rows with WHERE

SELECT reads data. SELECT name, age FROM users returns those two columns for every row. Add WHERE to keep only the rows that match a condition. Conditions use =, <>, <, >, <=, >= and can be combined with AND / OR.

SELECT name FROM users WHERE age >= 18 AND city = 'Almaty'

Note: SQL uses a single = for comparison, and text goes in single quotes.

Why it matters: real tables have millions of rows; WHERE is how you fetch only the few you need.