SQL-如何通过涉及多列的计算获得每行的最大值

Question

表1的每一行应在计算中找到包括表1和表2中的多列的最大值。表1由以下几列组成：ID，代码，Value1，Value2，Max_value表2由以下几列组成：ID，代码，Perc1，Perc2

**Table1**

ID=1 (value1=1000, Value2=5000, ID=21);   Max_Value=? 
ID=2 (value1=2000, Value2=4000, ID=21);   Max_Value=?
ID=3 (value1=1000, Value2=5000, ID=21);   Max_Value=?

**Table2**

ID=25 (Perc1=5.2%, Perc2=3.5%, Code=21);    
ID=26 (Perc1=3.1%, Perc2=8.6%, Code=21);   
ID=27 (Perc1=2.5%, Perc2=3.4%, Code=21)


** Calculation**

formula:
    𝑀𝑎𝑥𝑉𝑎𝑙𝑢𝑒=𝑀𝐴𝑋[(𝑉𝑎𝑙𝑢𝑒1 ∗𝑃𝑒𝑟𝑐1)+(𝑉𝑎𝑙𝑢𝑒2 ∗𝑃𝑒𝑟𝑐2)]
              WHERE Table1.Code=Table2.Code

Max_Value (Table1.Id=1, Table2.Id=25) = 227
Max_Value (Table1.Id=1, Table2.Id=26) = 461 (max for ID 1)
Max_Value (Table1.Id=1, Table2.Id=27) = 195

Max_Value (Table1.Id=2, Table2.Id=25) = 224
Max_Value (Table1.Id=2, Table2.Id=26) = 406 (max for ID 2)
Max_Value (Table1.Id=2, Table2.Id=27) = 186

Max_Value (Table1.Id=3, Table2.Id=25) = 401
Max_Value (Table1.Id=3, Table2.Id=26) = 695 (max for ID 3)
Max_Value (Table1.Id=3, Table2.Id=27) = 313

Answer 1

如果我理解正确，则需要join和row_number()：

select t12.*
from (select t1.*, t2.*,
             (t2.perc1 * t1.value1 + t2.perc2 * t1.value2) as calc,
             row_number() over (partition by t1.id order by (t2.perc1 * t1.value1 + t2.perc2 * t1.value2) desc) as seqnum
      from table1 t1 join
           table2 t2
           on t1.code = t2.code
     ) t12
where seqnum = 1;

尽管您在示例数据中看不到，但是您的代码和解释暗示了code中的table1列。