Question

我有一个名为值的表，其中包含3列 - 位置，值，日期

我想计算每月的平均值

到目前为止我已经

了

SELECT Location, Avg(value), date  
FROM Value  
GROUP BY Location, date

这会返回平均值，但是每天输入一个值，所以我每天平均而不是每月平均值，我怎样才能达到月平均值？

Answer 1

试试这个：

SELECT    Location,
          Avg(value),
          month(date),
          year(date)
FROM      Value
GROUP BY  Location,
          month(date),
          year(date)

Answer 2

如果您只想进行仅按月分组，则可以使用以下内容：

SELECT Location, Avg(value) AvgVal, Month(date) Mnth
FROM Value
GROUP BY Location, Month(date)

您甚至可以使用GROUPING SETS GROUP BY月，年，地点，然后为所有人提供总数：

SELECT Location, 
  Avg(value) AvgVal, 
  Month(dt) Mnth,
  Year(dt) Yr
FROM yourtable
GROUP BY 
  GROUPING SETS((Month(dt), Year(dt), Location), (Location));

请参阅SQL Fiddle with Demo

Answer 3

SELECT
     Location,
     year(date),
     month(date),
     Avg(value)
FROM
     Value
GROUP BY
     Location,
     year(date),
     month(date)

Answer 4

如果要将日期与一个月的第一天作为一天合并到一列中，也可以执行以下操作。

SELECT    Location,
          Avg(value),
          DateFromParts(Year(date), Month(date) , 1) AS FirstOfMonthDate
FROM      Value
GROUP BY  Location,
          DateFromParts(Year(date), Month(date) , 1)

SQL - 月平均值而不是每日平均值

4 个答案: