How to Always Return a Value from a MySQL Query, Even When No Results are Found?

Returning a Value Despite Null Results

When executing queries that retrieve a specific field based on an identifier, it's common to encounter situations where the ID is not found and the result set remains empty. However, certain scenarios demand the query to consistently return a value, even in the absence of a result.

Optimized Solution with IFNULL

One method to achieve this is by utilizing MySQL's IFNULL function, which evaluates the result of a query and returns a specified value if the result is null. This allows you to modify the query as follows:

SELECT IFNULL(
    (SELECT field1 FROM table WHERE id = 123 LIMIT 1),
    'not found'
);

In this case, the IFNULL function ensures that the query returns either the field value if the ID is found or the "not found" string if the ID is not found. This avoids the need for multiple subqueries and improves query efficiency.

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