有关SQL语句的问题

Question

select count(*) from dual where 'A0132' in (

select column_value
from table (select split(WMSYS.WM_concat(industrytypeno), ',')

      from map_industry mi
     where mi.newmaterial is not null

)

)
谁能帮我解答一下这段SQL的意思。

Answer 1

[code="java"]select split(WMSYS.WM_concat(industrytypeno), ',') from map_industry mi where mi.newmaterial is not null 查出来是一张表 a
select column_value from a 查出来是单列的表B
select count(*) from dual where 'A0132' in（B表的这一列）[/code]