Question

如果我有tblCust

c_id       Option         Numbers
10         1              2
5          1              1
10         2              1

我想返回数字最大的选项c_id = 10.我已经尝试了

 SELECT Option, MAX(Numbers) FROM tblCust WHERE c_id = 10

但没有运气

Answer 1

您没有指定DBMS，因此这是标准SQL

select *
from (
   select c_id, 
          option,
          max(option) over (partition by c_id) as max_opt
   from tblCust
   where c_id = 10
) t
where option = max_opt;

Answer 2

如果没有子查询，您可以对事物进行排序以获得最大的

SELECT  Option FROM tblCust
WHERE c_id = 10
ORDER BY Number DESC LIMIT 1

Answer 3

使用此：

SELECT Option, Numbers
FROM tblCust
WHERE c_id = 10
ORDER BY Numbers DESC
LIMIT 1

输出：

Option  Numbers
1       2

Answer 4

我认为max（）over（）的使用是针对Numbers而不是Option

select *
from (
   select c_id, 
          option,
          max(numbers) over (partition by c_id) as max_numbers
   from tblCust
   where c_id = 10
) t
where numbers = max_numbers;

但是，如果数据中有多条记录等于max（Numbers） - 并且您只想要一条结果记录 - 那么使用row_number（）可能是更好的选择。

select *
from (
       select c_id, 
              option,
              row_number() over (partition by c_id order by Numbers DESC, Option DESC) as rn
       from tblCust
       where c_id = 10
    ) AS t
where rn=1
;

注意在此处的over（）内的顺序，它首先放置最高的数字和选项，然后给出row_number值为1

SQL选择基于Max的列（其他列）

4 个答案: