? MySQL String Functions

? Quick Overview

MySQL String Functions are built-in functions used to manipulate and process text data. They help in formatting, searching, extracting, and modifying string values stored in database tables.

? Key Concepts

• Used to handle VARCHAR, CHAR, and TEXT data types
• Perform operations like concatenation, length checking, trimming
• Useful in SELECT queries and conditions
• Return processed string values

? Syntax / Theory

String functions are applied inside SQL queries, mostly within the SELECT statement.

FUNCTION_NAME(string, arguments)

? Common String Functions

1️⃣ LENGTH()

Returns the length of a string in characters.

// Get length of a string
SELECT LENGTH('MySQL Database');

2️⃣ CONCAT()

Combines multiple strings into one.

// Combine first name and last name
SELECT CONCAT('MySQL',' ','Server');

3️⃣ UPPER() & LOWER()

Convert string to uppercase or lowercase.

// Convert string to uppercase
SELECT UPPER('mysql');

// Convert string to lowercase
SELECT LOWER('MYSQL');

4️⃣ SUBSTRING()

Extracts a portion of a string.

// Extract 5 characters starting from position 1
SELECT SUBSTRING('Database',1,5);

5️⃣ TRIM()

Removes leading and trailing spaces.

// Remove extra spaces from string
SELECT TRIM('   MySQL   ');

? Live Output / Explanation

These functions return transformed string values directly in the query result. They are often used for formatting output, cleaning user input, or preparing reports.

? Interactive SQL Simulator

Test the functions live below. Enter a string and click a button to see the MySQL result.