GREATEST and LEAST in MySQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the GREATEST function do in MySQL?

The GREATEST function returns the largest value from a list of values. It compares all values and gives back the highest one.

beginner

What does the LEAST function do in MySQL?

The LEAST function returns the smallest value from a list of values. It compares all values and gives back the lowest one.

intermediate

How does GREATEST handle NULL values in MySQL?

If any value in the list is NULL, GREATEST returns NULL. NULL means unknown, so the result is unknown.

intermediate

How does LEAST handle NULL values in MySQL?

If any value in the list is NULL, LEAST returns NULL. NULL means unknown, so the result is unknown.

beginner

Write a MySQL query using GREATEST to find the highest score among three columns: score1, score2, score3.

SELECT GREATEST(score1, score2, score3) AS highest_score FROM your_table;

What will GREATEST(5, 10, 3) return?

A 3

B 5

C 10

D NULL

GREATEST returns the largest value, which is 10.

What will LEAST(7, 2, 9) return?

A 7

B NULL

C 9

D 2

LEAST returns the smallest value, which is 2.

What does GREATEST(4, NULL, 6) return in MySQL?

A NULL

B 6

C 4

D Error

If any value is NULL, GREATEST returns NULL.

Which function would you use to find the smallest value among columns in MySQL?

A LEAST

B MAX

C GREATEST

D MIN

LEAST returns the smallest value among the given values.

What will LEAST('apple', 'banana', 'cherry') return?

A 'cherry'

B 'apple'

C 'banana'

D NULL

LEAST compares strings alphabetically and returns 'apple' as it comes first.

Explain how GREATEST and LEAST functions work in MySQL and how they handle NULL values.

Think about comparing numbers or strings and what happens if one value is unknown.

Write a simple MySQL query using GREATEST to find the highest value among three columns in a table.

Use SELECT GREATEST(column1, column2, column3) AS alias FROM table;