SQL中关键字“GROUP”附近的语法不正确

对语句进行分组时遇到错误。这是我的密码

 DECLARE @avg_volume INT
 SELECT @avg_volume = ISNULL(AVG(Total_Volume), 0)
 FROM   ( SELECT    station_id ,
                    DATEPART(Year, date_time) AS YEAR ,
                    DATEPART(month, date_time) AS MONTH ,
                    CONVERT(DATE, date_time) AS DATE ,
                    DATENAME(weekday, date_time) AS weekday ,
                    SUM(volume) AS Total_volume
          FROM      rvtcs_data_aggregated_hourly
          GROUP BY  station_id ,
                    CONVERT(DATE, date_time) ,
                    DATEPART(month, date_time) ,
                    DATEPART(Year, date_time) ,
                    DATENAME(weekday, date_time)
        )
 GROUP BY station_id ,
        CONVERT(DATE, date_time) ,
        DATEPART(month, date_time) ,
        DATEPART(Year, date_time) ,
        DATENAME(weekday, date_time)
 ORDER BY DATEPART(Year, date_time) ,
        DATEPART(month, date_time) ,
        CONVERT(DATE, date_time)

 SELECT @avg_volume

我想做的是，通过一组conditionsInner查询从卷组中获取总和，结果如下

station_id  YEAR    MONTH   DATE            weekday Total_volume
7       2013    2   2013-02-21  Thursday    192
7       2013    2   2013-02-27  Wednesday   2699
7       2013    2   2013-02-28  Thursday    196
2       2013    3   2013-03-07  Thursday    192
7       2013    3   2013-03-07  Thursday    192

现在我想取平均值。任何帮助都会有帮助

我的表主表

station_id  date_time   volume

7   2013-02-21 00:00:00.000 96
7   2013-02-21 01:00:00.000 96
7   2013-02-27 00:00:00.000 356
7   2013-02-27 00:00:00.000 410
7   2013-02-27 00:00:00.000 471
7   2013-02-27 00:00:00.000 530
7   2013-02-27 00:00:00.000 338
7   2013-02-27 00:00:00.000 211
7   2013-02-27 00:00:00.000 159
7   2013-02-27 00:00:00.000 128
7   2013-02-27 00:00:00.000 96
7   2013-02-28 00:00:00.000 96
7   2013-02-28 01:00:00.000 100
7   2013-03-07 00:00:00.000 96
2   2013-03-07 00:00:00.000 96
2   2013-03-07 01:00:00.000 96
7   2013-03-07 01:00:00.000 96

期望输出：

station id     year  month     weekday    average_volume
  7            2013     2      Thursday     194

---

您的查询中几乎没有基本问题。您正在根据年月日等进行汇总并找到平均值。我没有看到任何年、月或站点id的过滤器。因此，我假设在最终select查询中会有多行，并且您正在选择一个变量。因此，您可能只能从变量中的第一行/最后一行获取值，当然这取决于顺序。您必须在此处对查询进行一些修改

此查询是否为您提供了正确的输出

SELECT  ISNULL(AVG(Total_volume), 0)
FROM    ( SELECT    station_id ,
                    DATEPART(year, date_time) AS YEAR ,
                    DATEPART(month, date_time) AS MONTH ,
                    CONVERT(DATE, date_time) AS DATE ,
                    DATENAME(weekday, date_time) AS weekday ,
                    SUM(volume) AS Total_volume
          FROM      rvtcs_data_aggregated_hourly
          GROUP BY  station_id ,
                    CONVERT(DATE, date_time) ,
                    DATEPART(month, date_time) ,
                    DATEPART(year, date_time) ,
                    DATENAME(weekday, date_time)
          ORDER BY  DATEPART(year, date_time) ,
                    DATEPART(month, date_time) ,
                    CONVERT(DATE, date_time)
        ) T; 

---

您的查询中几乎没有基本问题。您正在根据年月日等进行汇总并找到平均值。我没有看到任何年、月或站点id的过滤器。因此，我假设在最终select查询中会有多行，并且您正在选择一个变量。因此，您可能只能从变量中的第一行/最后一行获取值，当然这取决于顺序。您必须在此处对查询进行一些修改

此查询是否为您提供了正确的输出

SELECT  ISNULL(AVG(Total_volume), 0)
FROM    ( SELECT    station_id ,
                    DATEPART(year, date_time) AS YEAR ,
                    DATEPART(month, date_time) AS MONTH ,
                    CONVERT(DATE, date_time) AS DATE ,
                    DATENAME(weekday, date_time) AS weekday ,
                    SUM(volume) AS Total_volume
          FROM      rvtcs_data_aggregated_hourly
          GROUP BY  station_id ,
                    CONVERT(DATE, date_time) ,
                    DATEPART(month, date_time) ,
                    DATEPART(year, date_time) ,
                    DATENAME(weekday, date_time)
          ORDER BY  DATEPART(year, date_time) ,
                    DATEPART(month, date_time) ,
                    CONVERT(DATE, date_time)
        ) T; 

---

基于您想要做的事情，您不需要进行第二次显式聚合或排序。以平均数为例：

DECLARE @avg_volume INT
SELECT  @avg_volume = ISNULL(AVG(Total_Volume), 0)
FROM    ( SELECT    station_id ,
                    DATEPART(Year, date_time) AS "YEAR" ,
                    DATEPART(month, date_time) AS "MONTH" ,
                    CONVERT(DATE, date_time) AS "date" ,
                    DATENAME(weekday, date_time) AS weekday ,
                    SUM(volume) AS Total_volume
          FROM      rvtcs_data_aggregated_hourly
          GROUP BY  station_id ,
                    CONVERT(DATE, date_time) ,
                    DATEPART(month, date_time) ,
                    DATEPART(Year, date_time) ,
                    DATENAME(weekday, date_time)
        ) t;

您的特定错误是因为您在子查询上没有别名。关键字组不算作别名

你的一些列名是一个关键字，所以我引用了它们。这类词汇的列表如下所示

实际上，在编写这样的查询时，您不需要在select中包含所有列，因此您还可以执行以下操作：

DECLARE @avg_volume INT
SELECT  @avg_volume = ISNULL(AVG(Total_Volume), 0)
FROM    ( SELECT    SUM(volume) AS Total_volume
          FROM      rvtcs_data_aggregated_hourly
          GROUP BY  station_id ,
                    CONVERT(DATE, date_time) ,
                    DATEPART(month, date_time) ,
                    DATEPART(Year, date_time) ,
                    DATENAME(weekday, date_time)
        ) t;

---

基于您想要做的事情，您不需要进行第二次显式聚合或排序。以平均数为例：

DECLARE @avg_volume INT
SELECT  @avg_volume = ISNULL(AVG(Total_Volume), 0)
FROM    ( SELECT    station_id ,
                    DATEPART(Year, date_time) AS "YEAR" ,
                    DATEPART(month, date_time) AS "MONTH" ,
                    CONVERT(DATE, date_time) AS "date" ,
                    DATENAME(weekday, date_time) AS weekday ,
                    SUM(volume) AS Total_volume
          FROM      rvtcs_data_aggregated_hourly
          GROUP BY  station_id ,
                    CONVERT(DATE, date_time) ,
                    DATEPART(month, date_time) ,
                    DATEPART(Year, date_time) ,
                    DATENAME(weekday, date_time)
        ) t;

您的特定错误是因为您在子查询上没有别名。关键字组不算作别名

你的一些列名是一个关键字，所以我引用了它们。这类词汇的列表如下所示

实际上，在编写这样的查询时，您不需要在select中包含所有列，因此您还可以执行以下操作：

DECLARE @avg_volume INT
SELECT  @avg_volume = ISNULL(AVG(Total_Volume), 0)
FROM    ( SELECT    SUM(volume) AS Total_volume
          FROM      rvtcs_data_aggregated_hourly
          GROUP BY  station_id ,
                    CONVERT(DATE, date_time) ,
                    DATEPART(month, date_time) ,
                    DATEPART(Year, date_time) ,
                    DATENAME(weekday, date_time)
        ) t;

---

您需要命名子查询：

DECLARE @avg_volume INT
 SELECT @avg_volume = ISNULL(AVG(Total_Volume), 0)
 FROM   ( SELECT    station_id ,
                    DATEPART(Year, date_time) AS YEAR ,
                    DATEPART(month, date_time) AS MONTH ,
                    CONVERT(DATE, date_time) AS DATE ,
                    DATENAME(weekday, date_time) AS weekday ,
                    SUM(volume) AS Total_volume
          FROM      rvtcs_data_aggregated_hourly
          GROUP BY  station_id ,
                    CONVERT(DATE, date_time) ,
                    DATEPART(month, date_time) ,
                    DATEPART(Year, date_time) ,
                    DATENAME(weekday, date_time)

        ) AnyNameYouLikeButYouHaveToGiveOne --<-- Here

 GROUP BY station_id ,
        CONVERT(DATE, date_time) ,
        DATEPART(month, date_time) ,
        DATEPART(Year, date_time) ,
        DATENAME(weekday, date_time)
 ORDER BY DATEPART(Year, date_time) ,
        DATEPART(month, date_time) ,
        CONVERT(DATE, date_time)

 SELECT @avg_volume

---

您需要命名子查询：

DECLARE @avg_volume INT
 SELECT @avg_volume = ISNULL(AVG(Total_Volume), 0)
 FROM   ( SELECT    station_id ,
                    DATEPART(Year, date_time) AS YEAR ,
                    DATEPART(month, date_time) AS MONTH ,
                    CONVERT(DATE, date_time) AS DATE ,
                    DATENAME(weekday, date_time) AS weekday ,
                    SUM(volume) AS Total_volume
          FROM      rvtcs_data_aggregated_hourly
          GROUP BY  station_id ,
                    CONVERT(DATE, date_time) ,
                    DATEPART(month, date_time) ,
                    DATEPART(Year, date_time) ,
                    DATENAME(weekday, date_time)

        ) AnyNameYouLikeButYouHaveToGiveOne --<-- Here

 GROUP BY station_id ,
        CONVERT(DATE, date_time) ,
        DATEPART(month, date_time) ,
        DATEPART(Year, date_time) ,
        DATENAME(weekday, date_time)
 ORDER BY DATEPART(Year, date_time) ,
        DATEPART(month, date_time) ,
        CONVERT(DATE, date_time)

 SELECT @avg_volume

---

我想做的是从包含每小时数据的卷列中获取值的总和。因此，我将按年、月、站和工作日分组获取值的总和…然后我将根据我的要求获取所需的卷总和。现在我需要做的是从中取平均值。就像一个月内所有星期四的平均值一样。我要做的是从包含每小时数据的卷列中取值的总和。所以我要取按年、月、站和工作日分组的值的总和…然后我会根据我的要求得到所需的卷的总和。现在我需要做的是从中取平均值。就像一个月内所有周四的平均值一样。Msg 207，16级，状态1，第17行无效列名“date_time”。这就是我运行您的查询时得到的结果，注意：我有一列同名@satheshMsg 207，级别16，状态1，第17行无效的列名“date\u time”。这就是我在运行您的查询时得到的结果，注意：我有一个与@sathesh同名的列