SQL · Chapter 2 of 42

SQL Syntax

SQL statements end with a semicolon `;`. Keywords like SELECT, FROM, WHERE are case-insensitive but conventionally written in UPPERCASE.

String literals use single quotes: `'hello'`. Identifiers (table/column names) use no quotes, or double quotes for reserved words.

Syntax

SELECT column1, column2
FROM table_name
WHERE condition
ORDER BY column1;

Basic statement layout

SELECT columns FROM table [WHERE condition] [GROUP BY col] [ORDER BY col] [LIMIT n];

`-- single line` and `/* multi line */`.

Example 1 (sql)

-- Get top 3 oldest users
SELECT name, age FROM users
ORDER BY age DESC
LIMIT 3;

Output

name | age
Ben  | 30
Ana  | 25
Cara | 22

Read + sort + limit — the most common pattern.

Example 2 (sql)

SELECT * FROM users WHERE name = 'Ana';

Output

Ana | 25

String literals use single quotes.

💡 Note: Double quotes are for identifiers, single quotes are for values. Mixing them up is a common beginner error.