用法1：WHERENOTEXISTS或WHEREEXISTS WHEREEXISTS：查询结果包含任意一个子查询结果集则返回真；否则假 子查询： SELECT FROMmarcASa INTOTABLElt_data WHEREEXISTS(SELECTFROMmarcWHEREmatnr='10000312'AND(werks='1001'ORwerks='9001')) ANDmatnr='10000312' ORDERBYmatnr,werks INTOTABLE@DATA(lt_marc). 子查询： SELECT FROMmarcASa INTOTABLElt_d...