How to Correctly Subtract a Value from a MySQL Column?

Updating Columns by Subtracting a Value in MySQL

The question posed seeks to modify the points column in the username table using a MySQL query. The suggested query attempts to subtract 5 from the current value of the points column, but syntax issues hinder its execution.

To address this, the correct syntax for the query should be:

UPDATE a75ting.username
SET points = points - 5

Here's why the suggested query was incorrect:

• Missing Table Reference: The original query omitted the database and table names, leading to ambiguity. The syntax requires specifying the database (a75ting) and table (username) clearly.
• No Quotes Surrounding Value: Enclosing the subtraction expression in single quotes caused MySQL to interpret it as a constant string instead of an expression. Omitting the quotes informs MySQL to treat points - 5 as a mathematical operation that should be performed for each row.

By incorporating these corrections, the revised query correctly updates the points column by subtracting 5 from its current value for all rows in the username table.

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