SQL ORDER BY, LIMIT & DISTINCT Cheat Sheet

ORDER BY: sort the result

ORDER BY controls how returned rows are displayed. Use ASC for ascending order and DESC for descending order. When values can tie, add a second column so the order stays deterministic.

• ASC is the default
• DESC returns the largest values first
• Multiple columns provide stable tie-breaking

SELECT employee_name, salary
FROM employees
ORDER BY salary DESC, employee_name ASC;

LIMIT: return only the rows you need

LIMIT is useful for previews, pagination, and top-N analysis. Combine it with ORDER BY when 'first' or 'top' has a business meaning.

• LIMIT without ORDER BY does not guarantee which rows are returned
• Use it to inspect a dataset before writing a larger query

SELECT employee_name, salary
FROM employees
ORDER BY salary DESC
LIMIT 3;

DISTINCT: remove duplicate combinations

DISTINCT keeps one copy of each selected value combination. It is useful for exploring categories, but it should not be used to hide an incorrect join.

• DISTINCT applies to the complete selected row
• Check the join relationship before using DISTINCT after a join

SELECT DISTINCT department
FROM employees
ORDER BY department;

Combine all three

This query returns the first five unique departments alphabetically. Read it in execution order: choose the table, remove duplicate selected values, sort, then limit the output.

SELECT DISTINCT department
FROM employees
ORDER BY department ASC
LIMIT 5;