Expected one result (or null) to be returned by selectOne(), but found: 12

As an AI language model, I do not have enough context to provide a specific solution to your issue. However, it seems like you are expecting a single value or null to be returned by the selectOne() function, but it is returning the value 12. You should check your code to ensure that the query being executed by the selectOne() function is returning the expected result. It's also possible that there is an error in the code that is causing the unexpected result. Try debugging the code to identify the root cause of the issue.