单项选择题
A.distinct B.group by C.row_number D.having
A.SORT BY 用于分组汇总 B.SORT BY 用于局部排序，ORDER BY用于全局排序 C.使用完全一致 D.其他说法都不对
A.select * from a inner join b on a.id<>b.id B.select * from a where a.id in （select id from b） C.select sum（a.amt） as total from a where a.total>20 D.select * from a inner join b on a.id=b.id