A SEDE query to find questions a user has answered that don't have an acccepted answer. https://data.stackexchange.com/stackoverflow/query/1559991/find-questions-a-user-has-answered-that-dont-have-an-acccepted-answer

AnsweredButNoAcceptedAnswer.sql

DECLARE @UserId int = ##UserId##

SELECT
   Id AS [Post Link],
   -- TODO: Select user's answer score as well
   Score AS [Question Score] 
FROM
   Posts 
WHERE
   Id IN 
   (
      -- Select the question IDs of user's answers
      SELECT
         ParentId 
      FROM
         Posts 
      WHERE
         OwnerUserId = @UserId 
         AND PostTypeId = 2             -- Answers
   )
   AND AcceptedAnswerId IS NULL 
ORDER BY
   CreationDate DESC;