Stored procedures 对存储过程变量中的不同项进行计数

在存储过程中，我有value1、value2、value3、…、value8

价值结果将介于A和F之间

将值存储到变量中后，是否有方法查看value1~8中存储了多少不同的值

 example) 
 value1 = F; value2 = A; value3 = B; value4 = B;
 value5 = B; value6 = D; value7 = D; value8 = F;

然后在我的计数（distinct*）之后，结果应该是4个不同的组

select Value, COUNT(*) from (
select value1 as Value from sometable
union all 
select value2 as Value from sometable
union all 
select value3 as Value from sometable
union all 
select value4 as Value from sometable
union all 
select value5 as Value from sometable
union all 
select value6 as Value from sometable
union all 
select value7 as Value from sometable
union all 
select value8 as Value from sometable) as SomeTable
group by Value