Fetch records from one table where there's not a record in another

Question

SURVEYS table:

SurveyID
UserID
Question
Choice1
Choice2
Choice3

RESPONSES table:

UserID
SurveyID
         


        

Answer 1

Something like this I think should do?

SELECT * 
FROM Surveys s
WHERE s.UserID != 28 
AND s.SurveyID NOT IN (SELECT R.SurveyID FROM Responses R WHERE R.UserID = 28)

Answer 2

Using NOT IN:

SELECT s.*
  FROM SURVEYS s
 WHERE s.userid != 28
   AND s.surveyid NOT IN (SELECT r.survey_id
                            FROM RESPONSES r
                           WHERE r.userid = 28)

Using LEFT JOIN/IS NULL:

   SELECT s.*
     FROM SURVEYS s
LEFT JOIN RESPONSES r ON r.survey_id = s.surveyid
                     AND r.user_id = 28
    WHERE s.userid != 28
      AND r.userid IS NULL

Using NOT EXISTS:

SELECT s.*
  FROM SURVEYS s
 WHERE s.userid != 28
   AND NOT EXISTS (SELECT NULL
                     FROM RESPONSES r
                    WHERE r.userid = 28
                      AND r.survey_id = s.surveyid)

Of the options listed, the NOT IN and LEFT JOIN/IS NULL are equivalent though I prefer the NOT IN because it is more readable.