with TMP1 as (
    select
        row_number() over (order by TOTAL_VALUE) as ROW_NUM
        , cast(TOTAL_VALUE as real) as TOTAL_VALUE
    from CONVENIENCE
    where SURVEY_YEAR=2019 and KIND_CODE='100'
), TMP2 as (
    select
        count(*)%2 as ODD_OR_EVEN
        , round(cast(count(*) as real)/2, 0) as HALF_TOTAL
    from CONVENIENCE
    where SURVEY_YEAR=2019 and KIND_CODE='100'
)
select
    round(sum(case 
        when ODD_OR_EVEN=0 and (ROW_NUM=HALF_TOTAL or ROW_NUM=HALF_TOTAL+1) then TOTAL_VALUE
        when ODD_OR_EVEN=1 and ROW_NUM=HALF_TOTAL then TOTAL_VALUE
    end)/((ODD_OR_EVEN+1)%2+1), 0) as SA_MEDIAN
from TMP1 as T1, TMP2 as T2
;