一句sql搞定个人所得税计算

declare @salary numeric(18,2)
select @salary = 1000000 - 1600
select  sum(case when tax1 < 0 then 0 else tax1 end)  没减去速算扣除数_税款,
        sum(case when tax2 < 0 then 0 else tax2 end)  减去速算扣除数_税款
from
(
select  (case when @salary > left_point  then  case when @salary > right_point then right_point - left_point else @salary - left_point end else 0 end )  *  tax_percent  / 100 - agio_value  as tax1,
        (case when @salary > left_point  then  case when @salary > right_point then right_point - left_point else @salary - left_point end else 0 end )  *  tax_percent  / 100  as tax2 ,
        (case when @salary > left_point  then  case when @salary > right_point then right_point - left_point else @salary - left_point end else 0 end ) xxx,
         @salary salary, left_point, right_point, tax_percent/100 tax_percent, agio_value
from
 (
 select 0.00 left_point, 500.00 right_point,5.00 tax_percent,0.00 agio_value
 union all
 select 500.00,  2000.00,     10.00,      25.00 
 union all
 select 2000.00,         5000.00,     15.00,      125.00 
 union all
 select 5000.00,         20000.00,     20.00,      375.00 
 union all
 select 20000.00, 40000.00,     25.00,      1375.00 
 union all
 select 40000.00, 60000.00,     30.00,           3375.00 
 union all
 select 60000.00, 80000.00,     35.00,      6375.00 
 union all
 select 80000.00, 100000.00,     40.00,      10375.00 
 union all
 select 100000.00, 999999999999.00,    45.00,      15375.00 
 ) xxx
) yyy