假设表结构是:t1( 项目，金额)请参考下面sql代码写法，求出“差旅费”与总费用之占比，保留两位小数。select a.项目,round((sum(a.金额)/b.ze)*100,2) as 差旅费占比 from t1,(select sum(金额) as ze from t1) b where a.项目='差旅费' group by a.项目;
