How Can I Subtract a Value from a MySQL Database Column Without Errors?

Updating a Database Column by Subtracting a Value with MySQL

In MySQL, updating a database column by subtracting a value is straightforward. However, there's a crucial step you need to keep in mind to ensure a successful update: removing single quotes around the calculation.

Consider this example query:

UPDATE `a75ting`.`username` SET `points` = '`points` - 5'

This query won't work as intended because the single quotes around "points - 5`" transform the expression into a plaintext string. Instead, remove the single quotes to reference the "points" field and subtract 5 from its current value:

UPDATE a75ting.username
SET points = points - 5

With this corrected query, MySQL will correctly update the "points" column by subtracting 5 from each record's current value. Remember, when updating a column with calculations, including arithmetic operators like subtraction, skip the single quotes around the calculation.

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