get_var() returns NULL when empty string has been found

[flymikeGit]

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Issue Description

Description of Return values is "string|null Database query result (as string), or null on failure.". But, per https://core.trac.wordpress.org/ticket/30257, NULL will also be returned if the successful result is an empty string.

URL of the Page with the Issue]

https://developer.wordpress.org/reference/classes/wpdb/get_var/

Section of Page with the issue

Return values

Why is this a problem?

When my code found a return value of NULL, it triggered my error processing logic - instead of returning a successful result of an empty string.

Suggested Fix

Make clear that a NULL return may indicate an error, but could also be the successful result of an empty string.