oracle ORA-01427:单行子查询返回多个行
select * from (select a.*,rownum row_num from (select a.directflag,(select sheettypename from 
sheettype where id=(select sheettypeid from moduletype where moduleid=trim(a.sheetidruleid))) 
sheettypename,(select code||'-'||abbrev from channel where channelid=a.outcomecustomer)
outcustomer,(select code||'-'||abbrev from channel where channelid=a.incomecustomer) 
incustomer,(select balancetype from balancetypeset where id=a.balancetypeid)
 balancetype,(select goodsno||'-'||goodsname from goods where goodsid=a.goodsid) 
 goodsnanme,a.quantity,a.price,a.amount,a.accdate from channelaccount a where 1=1 
 and a.incomecustomer='acd488efdcc8f4a0ae2e42ebbe8e2f72') a) where row_num>0 and row_num<=20

执行报ORA-01427:单行子查询返回多个行
求高人指点
------解决方案--------------------
把=改为in试试
------解决方案--------------------

SELECT *

  FROM (SELECT A.*, ROWNUM ROW_NUM

          FROM (SELECT A.DIRECTFLAG,

                       (SELECT SHEETTYPENAME

                          FROM SHEETTYPE

                         WHERE ID =

                               (SELECT SHEETTYPEID

                                  FROM MODULETYPE

                                 WHERE MODULEID = TRIM(A.SHEETIDRULEID))) SHEETTYPENAME,

                       (SELECT CODE 
------解决方案--------------------
 '-' 
------解决方案--------------------
 ABBREV

                          FROM CHANNEL

                         WHERE CHANNELID = A.OUTCOMECUSTOMER) OUTCUSTOMER,

        &nbs