Question

我有下表：

Date      |   Product   |   Price 
06-12-17  |    1.1      |   10
06-12-17  |    1.2      |   20
06-12-17  |    1.3      |   30
06-12-17  |    1.4      |   40
05-12-17  |    1.1      |   20
05-12-17  |    1.2      |   20
05-12-17  |    1.3      |   40
05-12-17  |    1.4      |   40

我很难在SQL Server中找到一个可以给我这个结果的查询：

Date      |   Product |   Price 
06-12-17  |    1      |   25
05-12-17  |    1      |   30

我想要每天每件产品的平均价格

产品从1.1到24.4

Answer 1

如果您只需要product的左侧部分，cast至int，则使用结果值和date进行汇总。

select date, 
       cast(product as int) as product, 
       avg(price) as Price
from table1
group by date, cast(product as int)

<强>结果：

date        product Price
--------------------------
05-12-17    1       30
06-12-17    1       25

<强> DEMO

<强>更新

如果产品属于varchar数据类型，请使用cast两次。

select date, 
       cast(cast(product as dec(3,1)) as int) as product, 
       avg(price) as Price
from table1
group by date, cast(cast(product as dec(3,1)) as int)

<强> Varchar() Datatype DEMO

Answer 2

取决于您想要输出的数字。喜欢如果

FLOOR()
cast(product as int)转换为int

查询：

 SELECT
  Date,
  FLOOR(product) product, // This function can be replaced with above according to the output
  AVG(price) price

FROM your_table
GROUP BY date, FLOOR(product) order by Date

正如您所说输出为错误，您也可以尝试以下操作。

 SELECT
  Date,
  FLOOR(convert(float, product)) product, // This function can be replaced by FLOOR(cast(product as float))
  AVG(price) price

FROM your_table
GROUP BY date, FLOOR(convert(float, product)) order by Date;

Answer 3

假设每个产品值都有'。'（点）。否则从第2行删除-1。

SELECT Date,
   LEFT(CAST(product AS VARCHAR),charindex ('.',product) - 1),
   AVG(price)
FROM TABLE
GROUP BY Date, LEFT(CAST(product AS VARCHAR),charindex ('.',product) - 1);

Answer 4

试试这个：

     SELECT date,cast(product AS int) product,avg(Price) Price FROM (
     SELECT * FROM (VALUES 
     (cast('06-12-17' as date) ,    1.1      ,   10)
     ,(cast('06-12-17' as date) ,    1.2      ,   20)
     ,(cast('06-12-17' as date) ,    1.3      ,   30)
     ,(cast('06-12-17' as date) ,    1.4      ,   40)
     ,(cast('05-12-17' as date) ,    1.1      ,   20)
     ,(cast('05-12-17' as date) ,    1.2      ,   20)
     ,(cast('05-12-17' as date) ,    1.3      ,   40)
     ,(cast('05-12-17' as date) ,    1.4      ,   40)) a(Date      ,   
     Product   ,   Price ))x
     GROUP BY date,cast(product AS int)

SQL - AVG和Group by

4 个答案: