sql 根据条件选择最小值或最大值

Question

大家好，我正在尝试根据这些条件从一系列数据中选择最小值或最大值：

• 如果 setuptime 和 processtime cols 都是 0 选择 MIN(oprNum) （操作尚未开始，请先获取 oprnum）
• 如果 setuptime 和 process time 不为 0，则获取 max oprnum（主动操作）。

基于其中任何一个，我想要一行...请参阅随附的数据示例。谢谢！这是一个更大的查询的一部分，所以我需要每个 prodid 1 个输出行...

+------------+--------+---------+--------------------+--------------------+
| ProdId     | OprNum | Company | SetupTime          | ProcessTime        |
+------------+--------+---------+--------------------+--------------------+
| 12M0003381 | 10     | 12      | 1.3400000000000000 | 1.6100000000000000 |
+------------+--------+---------+--------------------+--------------------+
| 12M0003381 | 10     | 12      | 0.0000000000000000 | 0.0000000000000000 |
+------------+--------+---------+--------------------+--------------------+
| 12M0003381 | 15     | 12      | 1.0000000000000000 | 0.0000000000000000 |
+------------+--------+---------+--------------------+--------------------+
| 12M0003381 | 50     | 12      | 0.0000000000000000 | 0.0000000000000000 |
+------------+--------+---------+--------------------+--------------------+
| 12M0003381 | 60     | 12      | 0.0000000000000000 | 0.0000000000000000 |
+------------+--------+---------+--------------------+--------------------+
| 12M0003381 | 60     | 12      | 0.0000000000000000 | 0.0000000000000000 |
+------------+--------+---------+--------------------+--------------------+
| 12M0003381 | 70     | 12      | 0.0700000000000000 | 0.0400000000000000 |
+------------+--------+---------+--------------------+--------------------+
| 12M0003381 | 70     | 12      | 0.0000000000000000 | 0.0000000000000000 |
+------------+--------+---------+--------------------+--------------------+

Answer 1

更新的查询：基于上次评论

如果最大记录有 0 次，我想选择最后一条记录 有设置时间或处理时间。如果我将此行添加到您的小提琴中 ('12M0003381',80,12,0.00,0.00) 当我想要最后一行时，我得到了这一行 带有设置时间或处理时间

这个查询使用的逻辑是简单地计算一个额外的列weighted_value。在外部查询中，我们像以前一样使用 min over value 和 max over weighted value。

select 
  t.prodId,
  case when MAX(t.setuptime+ t.processtime)>0 then MAX(t.weighted_value) else MIN(t._value) end as value
from (
    select 
         prodID,
         oprnum as _value,
         setuptime,
         processtime,
         case 
           when setuptime+processtime>0 
           then oprnum 
           else NULL 
           end as weighted_value from tbl
    ) t
group by t.prodID

更新小提琴链接：http://sqlfiddle.com/#!6/b7ecb/20

请试试这个查询

select t1.ProdId, case when exists(
select 1 from tbl  t2 where t2.setuptime >0 or t2.Processtime>0 and t2.prodId=t1.prodId
)  then MAX(t1.oprNum) ELSE MIN(t1.oprNum) END
from tbl t1
group by ProdId

sql小提琴链接http://sqlfiddle.com/#!6/c52e22/1

Answer 2

一种方式：

SELECT 
    ProdId, 
    CASE WHEN SUM(SetupTime) + SUM(ProcessTime) = 0 THEN MIN(oprNum) ELSE MAX(oprNum) END 
FROM T
GROUP BY ProdId