下面的语句能写成一句完成任务吗?
SELECT "语文", round(sum(iif(语文>=90,1,0))/count(*)*100,2) AS 优秀率, round(sum(iif(语文>=75,1,0))/count(*)*100,2) AS 良好率, round(sum(IIf(语文>=65,1,0))/count(*)*100,2) AS 及格率, round(avg(语文),2) AS 平均分 FROM cj WHERE 班级=1;
union all
SELECT "语文", round(sum(iif(语文>=90,1,0))/count(*)*100,2) AS 优秀率, round(sum(iif(语文>=75,1,0))/count(*)*100,2) AS 良好率, round(sum(IIf(语文>=65,1,0))/count(*)*100,2) AS 及格率, round(avg(语文),2) AS 平均分 FROM cj WHERE 班级=2;
UNION ALL SELECT "语文", round(sum(iif(语文>=90,1,0))/count(*)*100,2) AS 优秀率, round(sum(iif(语文>=75,1,0))/count(*)*100,2) AS 良好率, round(sum(IIf(语文>=65,1,0))/count(*)*100,2) AS 及格率, round(avg(语文),2) AS 平均分 FROM cj WHERE 班级=3;