MySQL UNHEX()

The UNHEX() function is a build-in function in MySQL that converts a hexadecimal string to its corresponding binary string. Useful when we have data stored in hexadecimal format we can use UNHEX() function to convert it to the original binary form making it usable and understandable.

Syntax

UNHEX(val);

• val: A hexadecimal string to be converted to its corresponding binary form.

Example

The below example shows how UNHEX() function works.

CREATE TABLE documents (
    id INT PRIMARY KEY,
    content BLOB
);

INSERT INTO documents (id, content) VALUES (1, UNHEX('636F6465636164656D79'));

SELECT HEX(content) AS 'hex-content', CAST(content AS CHAR) AS readable_content
FROM documents
WHERE id = 1;

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The output of the above code will be: