Question

我有一个包含大量列的表，但我只需要从表中返回5列：

Name | Charge Code | Charge Amount | Modifier | Date

我希望仅根据“不同名称”，“费用代码”，“费用金额”和“修改符”返回字段。日期可以是记录存在的最新日期。我怎么能这样做？

目前我有：

Select 
    Name, Charge_code, Charge_amount, Modifier, Date
From 
    Table1
group by 
    Name, Charge_code, Charge_amount, Modifier

但是，当我这样做时，它告诉我日期在选择列表中无效，因为它不包含在聚合函数或组中。我不希望按功能原因在组中包含Date，然后它将返回一堆不必要的无关行。但我确实希望日期显示该人收取该金额的最新日期。

我也试过

Select 
    Date, Distinct Name, Charge_Code, Charge_amount, Modifier
From 
    Table 1

任何想法都会对我有所帮助。

由于

Answer 1

典型的方法是使用row_number()：

select Name, ChargeCode, ChargeAmount, Modifier, Date
from (select t.*,
             row_number() over (partition by Name, ChargeCode, ChargeAmount, Modifier
                                order by date desc
                               ) as seqnum
      from t
     ) t
where seqnum = 1;

Answer 2

SELECT distinct  main.Name, main.ChargeCode, main.ChargeAmount, main.Modifier,  
                 b.Date
FROM Table1  as main
Outer Apply (Select Top 1 Date
            from Table1 as sub
            where main.Name = sub.Name and main.ChargeCode = sub.ChargeCode and   main.ChargeAmount = sub.ChargeAmount and main.Modifier = sub.Modifier
            Order by sub.Date desc
             ) b

Answer 3

您也可以尝试这一点，简单易行

Select name, 
    charge_code, 
    charge_amount, 
    modifier, 
    max(date) date
From table1
Group by name, charge_code, charge_amount, modifier

SQL返回不同的结果和一个不必是不同的列

3 个答案: