排名的子查询未提供期望的结果Sybase ASE

问题描述

具有排名功能的sql QUERY：

        select availability_stat from (select availability_stat,row_number() 
        over (partition by sop_ckey order by 
        case availability_stat when 'ONLINE' then 1 
        when 'NEARLINE' then 2 when 'OFFLINE' then 3 end) 
        as rownumber from arc_address where study_ckey = 849) 
        as arc_address_with_rownumber 
        where rownumber = 1 group by availability_stat

输出：

    study_ckey|sop_ckey|availability_stat|rownumber|
    ----------|--------|-----------------|---------|
           849|     955|NEARLINE         |        1|
           849|     955|ONLINE           |        3|
           849|     955|OFFLINE          |        2|
           849|     957|NEARLINE         |        1|
           849|     960|NEARLINE         |        1|
           849|     960|ONLINE           |        2|
           849|     963|NEARLINE         |        1|
           849|     963|OFFLINE          |        2|
           849|     971|NEARLINE         |        1|
           849|     971|ONLINE           |        2|
           849|     973|NEARLINE         |        1|
           849|     973|OFFLINE          |        2|

SYBASE QUERY尝试使用子查询：

        select aa.study_ckey,aa.sop_ckey,aa.availability_stat,(select count(distinct availability_stat) 
        from arc_address aa2
        where aa2.sop_ckey = aa.sop_ckey
        and aa2.availability_stat < aa.availability_stat 
        or aa2.availability_stat = aa.availability_stat ) as rownumber
       from arc_address aa 
        where aa.study_ckey = 849 
        order by sop_ckey

输出：

study_ckey|sop_ckey|availability_stat|rownumber|
----------|--------|-----------------|---------|
       849|     955|NEARLINE         |        1|
       849|     955|ONLINE           |        3|
       849|     955|OFFLINE          |        2|
       849|     957|NEARLINE         |        1|
       849|     960|NEARLINE         |        1|
       849|     960|ONLINE           |        2|
       849|     963|NEARLINE         |        1|
       849|     963|OFFLINE          |        2|
       849|     971|NEARLINE         |        1|
       849|     971|ONLINE           |        2|
       849|     973|NEARLINE         |        1|
       849|     973|OFFLINE          |        2|

排名未按预期进行，即

在线-1， 近线-2， 离线-3 可能我不在这里使用case语句，但是case语句甚至使结果集更糟。请提出建议。

解决方法

达到相同并共享解决方案

        select sop_ckey,availability_stat,case when availability_stat = 'ONLINE' then 1
                             when availability_stat = 'NEARLINE' then 2
                             when availability_stat = 'OFFLINE' then 3
                         end as rank_value
        into #tmp
        from arc_address aa1 where study_ckey = 849
        group by sop_ckey,availability_stat

      
        select availability_stat
            from (
                    select availability_stat,(select 1 + count(distinct t2.availability_stat)
                    from #tmp t2
                    where t2.sop_ckey = t1.sop_ckey and 
                    t2.rankvalue < t1.rankvalue) as new_rank
                    from #tmp t1
                 )
        as arc_address_with_rownumber
        where  newrank = 1
        group by availability_stat