How to Denormalize a Normalized Table Using SQL in MySQL

Share this post!

Vote this!

Often times, we sacrifice some usability in our data in order to follow nth-normal form in our database architecture.

 The following is a trick that allows us to retrieve name-value pairs of data as denormalized column-value pairs.

 Let's take the case of a user settings table. A typical denormalized user settings table may look like this:

CREATE TABLE denormalized_settings (
    user_id int NOT NULL,
    setting1 varchar(255) NULL,
    setting2 varchar(255) NULL,
    setting3 varchar(255) NULL,
    setting4 varchar(255) NULL
);

INSERT INTO denormalized_settings (user_id, setting1, setting2, setting3, setting4) VALUES
    (1, 'hi', '0', '1', '0'),
    (2, '0', '1', NULL, '1'),
    (3, '1', '0', '1', NULL);

More...