select a.col1,a.col2,b.col1,b.col2,c.col1,c.col2,max(b.xxDate)from 表1 a join 表2 b on a.xxID=b.xxID join 表3 c on a.xxID=c.xxIDgroup by a.col1,a.col2,b.col1,b.col2,c.col1,c.col2
