SQL语句怎么实现几列数据合并成一条??答:select DISTINCT ta.sCode, ta.sQuality, ta.fNum, tb.sQuality, tb.fNum, tc.sQuality, tc.fNum from (select sCode, sQuality, max(fNum) as fNum from 表2 where sQuality = 'a'group by sCode, sQuality ) as ta left join (select sCode, sQuality, max(fNum) as fNum ...