How to Return a Value Even When a Database Query Returns an Empty Result Set?

Returning a Value Despite Empty Result Sets

When querying a database for a specific value, it can be challenging to handle situations where the result set is empty. Here is an efficient solution to guarantee a non-null return value even when no results exist:

MySQL offers the IFNULL function, which resolves the problem effortlessly:

<code class="sql">SELECT IFNULL( (SELECT field1 FROM table WHERE id = 123 LIMIT 1) ,'not found');</code>

In this query, if the subquery returns no value (due to an invalid id or empty result set), the IFNULL function supplies the alternative value, such as 'not found' in this example. As a result, you will always receive a non-null value in a single query statement without executing the subquery twice.

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