create table A(ID int, SERIES decimal(6,1), ACTUALAMOUNT int)
insert a
select 1 ,1.0 ,2 union all
select 1 ,1.5 ,5 union all
select 2 ,1.3 ,3 union all
select 2 ,2 ,4


create table B(ID int, QTY decimal(6,1))
insert b
select 1 ,1 union all
select 2 ,2.5




select a.*,显示=case when a.SERIES*b.QTY<=a.ACTUALAMOUNT then '正确' else '错误' end
from a inner join b on a.id=b.id

/*
ID          SERIES                                  ACTUALAMOUNT 显示
----------- --------------------------------------- ------------ ----
1           1.0                                     2            正确
1           1.5                                     5            正确
2           1.3                                     3            错误
2           2.0                                     4            错误

(4 行受影响)

*/