看一條sql

Question

SELECT DISTINCT IndividualData.recruitFacultyId,ExamQualification.schoolDesc  FROM IndividualData left join ExamQualification on IndividualData.examineeNo =ExamQualification.examineeNo 
這樣回查出數據.
但是我求count時候出錯.SELECT COUNT(DISTINCT IndividualData.recruitFacultyId,ExamQualification.schoolDesc) AS totalCount FROM IndividualData left join ExamQualification on IndividualData.examineeNo =ExamQualification.examineeNo應該怎麼寫啊.先謝謝了

Answer 1

SELECT COUNT(DISTINCT IndividualData.recruitFacultyId) AS totalCount FROM IndividualData left join ExamQualification on IndividualData.examineeNo =ExamQualification.examineeNo
或者
SELECT COUNT(DISTINCT ExamQualification.schoolDesc) AS totalCount FROM IndividualData left join ExamQualification on IndividualData.examineeNo =ExamQualification.examineeNo

Answer 2

或者
SELECT COUNT(DISTINCT *) AS totalCount FROM IndividualData left join ExamQualification on IndividualData.examineeNo =ExamQualification.examineeNo

Answer 3

select count(*)
  from (SELECT DISTINCT IndividualData.recruitFacultyId,
                        ExamQualification.schoolDesc
          FROM IndividualData
          left join ExamQualification on IndividualData.examineeNo =
                                         ExamQualification.examineeNo);