带有条件数据计数的SQL select语句

Question

我想使用SQL select语句有条件地返回列数据。我正在使用Oracle SQL Developer。

输出应如下所示：

REP_START_YEAR  UNIVERSITY_CODE     STUDENT_OEN     OEN_COUNT
2012            UNIVERSITYA         999999999       3
2012            UNIVERSITYA         000000000       0
2012            UNIVERSITYA         Other           2105

这是我到目前为止所提出的：

select enrol.Rep_Start_Year, uni.university_code,  enrol.student_OEN, count(*) as Invalid_OEN_Count

from (select enrol.Rep_Start_Year, uni.university_code, enrol.student_OEN, CASE WHEN enrol.student_OEN  not in ('999999999','000000000')
                            THEN 'Other'
                          ELSE enrol.student_OEN
                          END as student_OEN
from edcs_unistat.ustat_enrolment_data enrol) 

inner join    edcs_unistat.uni_institution_type uniinst
on        enrol.uni_institution_type_ID = uniinst.uni_institution_type_id

inner join    
(select u.UNIVERSITY_ID,
    (case 
        when U.UNIVERSITY_CODE = 'DOMC' then 'CARL'
        when U.UNIVERSITY_CODE = 'NOSM-LAKE' then 'NOSM'
        when U.UNIVERSITY_CODE = 'NOSM-LAUR' then 'NOSM'
        when U.UNIVERSITY_CODE = 'LAUR-ALGM' then 'ALGM'
        when U.UNIVERSITY_CODE = 'LAUR-HRST' then 'HRST'
        when U.UNIVERSITY_CODE = 'DOMC' then 'CARL'
        else U.UNIVERSITY_CODE 
     end) as university_code
from edcs_core.university u) uni
on          uniinst.university_id = uni.university_id

inner join  edcs_unistat.reg_status_type regstatus
on          enrol.reg_status_type_id = regstatus.reg_status_type_id

inner join  edcs_unistat.fee_cat_type feetyp
on          enrol.fee_cat_type_id = feetyp.fee_cat_type_id

group by    enrol.Rep_Start_Year, uni.university_code,  enrol.student_OEN

order by    enrol.Rep_Start_Year, uni.university_code, enrol.student_OEN

Answer 1

select Institution, Student_Number, count(*)
from (select Institution, CASE WHEN Student_Number  not in ('999','000')
                            THEN "Other"
                          ELSE Student_Number
                          END as Student_Number
      from Enrolment)
group by Institution, Student_Number;