SUBSTRING and LEFT/RIGHT in MySQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the SUBSTRING function do in MySQL?

SUBSTRING extracts a part of a string starting from a specified position for a given length.

beginner

How does the LEFT function work in MySQL?

LEFT returns the leftmost characters from a string, based on the number of characters you specify.

intermediate

What is the difference between SUBSTRING and LEFT functions?

SUBSTRING can start extracting from any position in the string, while LEFT always starts from the beginning (left side).

beginner

How does the RIGHT function work in MySQL?

RIGHT returns the rightmost characters from a string, based on the number of characters you specify.

beginner

Write a MySQL query to get the first 5 characters of the string 'HelloWorld'.

SELECT LEFT('HelloWorld', 5); -- This returns 'Hello'

What will SUBSTRING('Database', 3, 4) return?

A taba

B abas

C Data

D base

SUBSTRING starts at position 3 and takes 4 characters: 'taba'.

Which function extracts characters from the right side of a string?

A RIGHT

B LEFT

C SUBSTRING

D MID

RIGHT extracts characters from the right end of the string.

What does LEFT('OpenAI', 3) return?

A pen

B Ope

C AI

D enA

LEFT returns the first 3 characters from the left: 'Ope'.

If you want to extract characters starting from the 2nd character to the end, which function and syntax is correct?

A RIGHT(string, 2)

B LEFT(string, 2)

C SUBSTRING(string, 2)

D SUBSTRING(string, 1, 2)

SUBSTRING(string, 2) extracts from the 2nd character to the end.

What will RIGHT('Database', 4) return?

A Data

B ase

C taba

D base

RIGHT returns the last 4 characters: 'base'.

Explain how to use SUBSTRING, LEFT, and RIGHT functions to extract parts of a string in MySQL.

Think about where you want to start and how many characters you want.

Describe a real-life scenario where you might use LEFT or RIGHT functions in a database query.

Consider common string parts like prefixes or suffixes.