Introduction to MySQL Functions

MySQL provides a wide range of built-in functions that allow you to perform various operations on data. In this guide, we'll focus on two essential categories of functions: mathematical and string functions. These functions can help you manipulate and analyze data in your database effectively.


Mathematical Functions

MySQL offers a variety of mathematical functions to perform operations on numeric data. Some common mathematical functions include:

  • ABS(x): Returns the absolute value of a number.
  • ROUND(x, d): Rounds a number to a specified number of decimal places (d).
  • CEIL(x): Returns the smallest integer greater than or equal to x.
  • FLOOR(x): Returns the largest integer less than or equal to x.
  • POWER(x, y): Returns x raised to the power of y.

String Functions

MySQL's string functions enable you to manipulate and analyze text data. Some common string functions include:

  • CONCAT(str1, str2, ...): Concatenates two or more strings together.
  • LENGTH(str): Returns the length of a string in characters.
  • UPPER(str): Converts a string to uppercase.
  • LOWER(str): Converts a string to lowercase.
  • LEFT(str, len): Returns the leftmost len characters from a string.

Examples of Using Functions

Let's see some examples of using these functions. Consider a table called "products" with a column named "price," and another table called "customers" with a column named "name." You can use functions like this:

            -- Mathematical function example: Round the price to two decimal places
            SELECT product_name, ROUND(price, 2) AS rounded_price FROM products;
            
            -- String function example: Convert customer names to uppercase
            SELECT UPPER(name) AS uppercase_name FROM customers;

These queries demonstrate the use of mathematical and string functions in MySQL.


Conclusion

MySQL's mathematical and string functions are valuable tools for data manipulation and analysis. You've learned about some common functions in each category and seen examples of their usage. As you delve deeper into SQL, mastering these functions will empower you to work with data more efficiently.