因为您想突出显示两个表之间的差异。你应该按总和分组并比较总和的连续性。使用完全外部连接，因为您希望显示两侧的差异，如下所示：

select *,
CASE 
when a.cnt = b.cnt then 'Match' 
else 'Mismatch' 
end as Result from
(select sum,count(1) as cnt from table1 group by sum) a
full join
(select sum,count(1) as cnt from table2 group by sum) b
on a.sum=b.sum

sql fiddle演示
输出如下所示：

试试这个

select t1.id, t1.sum,
    CASE 
        when t1.sum = t2.sum then 'Match' 
        else 'Mismatch' 
    end
    as Compare
    from table1 t1 
    inner join table2 t2 on t1.id = t2.id

你想加入吗 id ?

select 
    t1.id, 
    t1.sum, 
    case when t1.sum = t2.sum then 'Match' else 'Mismatch' end as result
from table1 t1
inner join table2 t2 on t2.id = t1.id

或者，如果 id 我们不做数学，你可能想用 row_number() :

select 
    t1.id id1, 
    t1.sum sum1, 
    t2.id id2,
    t2.sum sum2,
    case when t1.sum = t2.sum then 'Match' else 'Mismatch' end as result
from (select t1.*, row_number() over(order by id) rn from table1 t1) t1
inner join ((select t2.*, row_number() over(order by id) rn from table2 t2) t2 
    on t2.rn = t1.rn

最后：如果两个表中的行数可能不同，请使用 full join 而不是 inner join （如果数据库支持）：

select 
    t1.id id1, 
    t1.sum sum1, 
    t2.id id2,
    t2.sum sum2,
    case when t1.sum = t2.sum then 'Match' else 'Mismatch' end as result
from (select t1.*, row_number() over(order by id) rn from table1 t1) t1
full join (select t2.*, row_number() over(order by id) rn from table2 t2) t2 
    on t2.rn = t1.rn