mysql 如何将女学生中低于总平均成绩的成绩提高5%?

Question

mysql&gt; desc SC ; Field Type Null Key Default Extra SID int(11) NO PRI NULL CID int(11) NO PRI NULL GRADE int(11) YES NULL 3 rows in set (0.00 sec) mysql&gt; desc S ; Field Type Null Key Def

阿神 · Answer

begin
declare n_avg  number;
select avg(grade) into n_avg from SC;
update SC set GRADE = GRADE*1.05 where grade

阿神 · Answer

select @avgs:=(select avg(grade) from SC);
update SC set GRADE = (GRADE+GRADE*0.05) where GRADE < @avgs and SID in (select SID from S where SEX = 1) ;