DDLS报错数据类型冲突：data type conflict in a selection 解决办法

@AbapCatalog.sqlViewName: 'ZCDSV_FCS'
@AbapCatalog.compiler.CompareFilter: true
@ACCESSCONTROL.AUTHORIZATIONCHECK: #CHECK
@EndUserText.label: 
define view Z_DDLS_FCS as select from pbim as A
inner join pbed as B on A.bdzei = B.bdzei 
inner join mara as C on A.matnr = C.matnr
left outer join marc as D on A.matnr = D.matnr and A.werks = D.werks
left outer join makt as E on A.matnr = E.matnr and E.spras = '1'
{      A.matnr,
       A.werks,
       C.mtart,
       C.mstae,
       D.maabc,
       D.plifz,
       D.rgekz,
       D.dispo,
       D.ekgrp,
       B.plnmg,
       B.perxx,
       E.maktx   
} 

上面代码报错

 解决办法：1后面放空格

left outer join makt as E on A.matnr = E.matnr and E.spras = '1 '