MySQL HEX() String Function

MySQL HEX() String Function

The MySQL HEX() string function converts a string or a number to its hexadecimal representation. This function is essential for encoding data in a hexadecimal format in SQL queries.

Syntax

SELECT HEX(expression) AS result
FROM table_name;

The HEX() function has the following components:

  • expression: The string or number to be converted to hexadecimal.
  • result: An alias for the resulting hexadecimal representation.
  • table_name: The name of the table from which to retrieve the data.

Example MySQL HEX() String Function

Let's look at some examples of the MySQL HEX() string function:

Step 1: Using the Database

USE mydatabase;

This query sets the context to the database named mydatabase.

MySQL USE DATABASE

Step 2: Creating a Table

Create a table to work with:

CREATE TABLE sample_strings (
    id INT AUTO_INCREMENT PRIMARY KEY,
    value VARCHAR(255) NOT NULL
);

This query creates a table named sample_strings with columns for id and value.

MySQL CREATE TABLE

Step 3: Inserting Initial Rows

Insert some initial rows into the table:

INSERT INTO sample_strings (value)
VALUES ('Hello'),
       ('MySQL'),
       ('Hexadecimal'),
       ('Function'),
       ('Example');

This query inserts five rows into the sample_strings table.

MySQL INSERT INTO TABLE

Step 4: Using HEX() with WHERE Clause

Use the HEX() function to convert a string to its hexadecimal representation:

SELECT value, HEX(value) AS hex_value
FROM sample_strings;

This query retrieves the value column from the sample_strings table and returns the hexadecimal representation of the string.

MySQL HEX() WITH WHERE CLAUSE

Step 5: Using HEX() with Multiple Columns

Use the HEX() function with multiple columns:

SELECT id, value, HEX(value) AS hex_value
FROM sample_strings;

This query retrieves the id and value columns from the sample_strings table and returns the hexadecimal representation of the string.

MySQL HEX() WITH MULTIPLE COLUMNS

Step 6: Using HEX() with Constants

Use the HEX() function with constants:

SELECT HEX('Example') AS hex_example, HEX(255) AS hex_255;

This query retrieves the hexadecimal representation of the constant string 'Example' and the constant number 255.

MySQL HEX() WITH CONSTANTS

Conclusion

The MySQL HEX() function is a powerful tool for encoding data in a hexadecimal format in SQL queries. Understanding how to use the HEX() function is essential for effective data querying and analysis in MySQL.