在sql查询中返回0而不是任何内容

Question

如何返回显示0响应的行？此查询返回4个ID中的3个和响应数量，但Id 3没有显示，因为它有0个响应。我想它与0

SELECT Count(sr.id) AS 'Responses', 
     qpa.possibleanswertext, 
     qpa.id 
FROM caresplusparticipantsurvey.questionpossibleanswer AS qpa 
     JOIN caresplusparticipantsurvey.surveyresponse AS sr 
     ON qpa.id = sr.questionpossibleanswerid 
WHERE (qpa.id BETWEEN 1 AND 4) 
     AND (sr.surveyid IN (SELECT surveyid 
          FROM caresplusparticipantsurvey.surveyresponse AS 
            sr 
          WHERE sr.questionpossibleanswerid = 138)) 
GROUP BY qpa.possibleanswertext, 
      qpa.id 

---

99 Very Useful           1 
    26 Somewhat useful           2 
    33 I did not complete this CORE requirement this year 4 

Answer 1

显示

更改join到left join，将使用NULL的不匹配行：

left join CaresPlusParticipantSurvey.SurveyResponse ... 

您还需要将您的过滤器移至ON部分，因此删除此：

and (sr.SurveyId in (select SurveyId from CaresPlusParticipantSurvey.SurveyResponse as  sr where sr.QuestionPossibleAnswerId = 138)) 

，改变你的加入到这一点：

left join CaresPlusParticipantSurvey.SurveyResponse AS sr 
    ON qpa.id = sr.questionpossibleanswerid 
    AND sr.SurveyId IS NULL OR sr.SurveyId in (
     select SurveyId 
     from CaresPlusParticipantSurvey.SurveyResponse as sr 
     where sr.QuestionPossibleAnswerId = 138 
    ) 

Answer 2

; with CTE as 
     (
     ... your query here ... 
     ) 
select * 
from CTE 
union all 
select 0 
,  null 
,  null 
where not exists 
     (
     select * 
     from CTE 
     )