Sql 分组方式和顺序_Sql_Group By_Mariadb_Sql Order By

Sql 分组方式和顺序

sql mariadb

Sql 分组方式和顺序,sql,group-by,mariadb,sql-order-by,Sql,Group By,Mariadb,Sql Order By,我有一个非常简单的Maria DB用于家庭自动化。这是我的ER的精华： TelldusActionsPerformed是一个日志表。它用于跟踪在不同时间执行的非常不同的操作（如温度测量、车门关闭、电源开关打开等）我使用以下查询获取感兴趣的数据： SELECT TelldusActionsPerformed.PerformedTime AS TelldusActionsPerformed_PerformedTime, TelldusUnits.Name AS TelldusUn

我有一个非常简单的Maria DB用于家庭自动化。这是我的ER的精华：

TelldusActionsPerformed

是一个日志表。它用于跟踪在不同时间执行的非常不同的操作（如温度测量、车门关闭、电源开关打开等）

我使用以下查询获取感兴趣的数据：

SELECT
    TelldusActionsPerformed.PerformedTime AS TelldusActionsPerformed_PerformedTime,
    TelldusUnits.Name AS TelldusUnits_Name,
    TelldusActionValues.ActionValue AS TelldusActionValues_ActionValue,
    TelldusActionValueTypes.Name AS TelldusActionValueTypes_Name
FROM
    TelldusActions
    INNER JOIN TelldusUnits ON TelldusActions.FK_TelldusUnit_Id = TelldusUnits.Id
    INNER JOIN TelldusActionTypes ON TelldusActions.FK_TelldusActionType_Id = TelldusActionTypes.Id
    INNER JOIN TelldusActionValues ON TelldusActions.FK_TelldusActionValue_Id = TelldusActionValues.Id
    INNER JOIN TelldusActionValueTypes ON TelldusActionValues.FK_TelldusActionValueType_Id = TelldusActionValueTypes.Id 
    INNER JOIN TelldusActionsPerformed ON TelldusActionsPerformed.FK_TelldusAction_Id = TelldusActions.Id
    WHERE TelldusUnits.Name IN ("Grovkök golvtermostat", "Huvudtermostat", "Uterum golvtermostat")
AND TelldusActionValueTypes.Name IN ("watt","temp")
ORDER BY TelldusActionsPerformed.PerformedTime DESC

这给了我一个结果集，如下所示

我想优化查询，只返回

TelldusUnits.Name

TelldusActionValueTypes.Name

字段的绝对最新（时间）唯一组合：

我相信我需要

按TelldusUnits.Name，TelldusActionValueTypes.Name进行分组才能得到唯一的组合？是否可以将我的搜索结果限制为仅使用SQL的TelldusUnits.Name
+TelldusActionValueTypes.Name
字段的最新唯一组合？怎么做
编辑1：
如果我开箱即用地运行Murillo先生的脚本（我只是从_UNIXTIME（）添加的，在我的原始问题中忘记了）：
我得到以下结果集：

TelldusActionsPerformed.PerformedTime DESC的订单让我感到困惑。该表似乎不是根据PerformedTime排序的后代？
（PerformedTime
，UNIX时间戳的数据类型为int（11））
编辑2：
关于Murillo先生通信的下一次更新给了我一个更好的分类：
SELECT
    FROM_UNIXTIME(MAX(TelldusActionsPerformed.PerformedTime)) AS TelldusActionsPerformed_PerformedTime,
    TelldusUnits.Name AS TelldusUnits_Name,
    TelldusActionValues.ActionValue AS TelldusActionValues_ActionValue,
    TelldusActionValueTypes.Name AS TelldusActionValueTypes_Name

FROM
    TelldusActions
    INNER JOIN TelldusUnits ON TelldusActions.FK_TelldusUnit_Id = TelldusUnits.Id
    INNER JOIN TelldusActionTypes ON TelldusActions.FK_TelldusActionType_Id = TelldusActionTypes.Id
    INNER JOIN TelldusActionValues ON TelldusActions.FK_TelldusActionValue_Id = TelldusActionValues.Id
    INNER JOIN TelldusActionValueTypes ON TelldusActionValues.FK_TelldusActionValueType_Id = TelldusActionValueTypes.Id
    INNER JOIN TelldusActionsPerformed ON TelldusActionsPerformed.FK_TelldusAction_Id = TelldusActions.Id
WHERE TelldusUnits.Name IN ("Grovkök golvtermostat", "Huvudtermostat", "Uterum golvtermostat")
AND TelldusActionValueTypes.Name IN ("watt","temp")
GROUP BY TelldusUnits.Name, TelldusActionValues.ActionValue, TelldusActionValueTypes.Name
ORDER BY MAX(TelldusActionsPerformed.PerformedTime) DESC


还有一个细节需要处理（根据我最初的问题：我只希望查询返回绝对最新的（时间）TelldusUnits.Name
+TelldusActionValueTypes.Name
字段的唯一组合。
没错，如果需要最新时间，则需要添加不考虑TelldusActionsPerformed.PerformedTime的GROUP BY子句。请尝试此脚本
SELECT
    --TelldusActionsPerformed.PerformedTime AS TelldusActionsPerformed_PerformedTime,
    MAX(TelldusActionsPerformed.PerformedTime) AS TelldusActionsPerformed_PerformedTime,
    TelldusUnits.Name AS TelldusUnits_Name,
    TelldusActionValues.ActionValue AS TelldusActionValues_ActionValue,
    TelldusActionValueTypes.Name AS TelldusActionValueTypes_Name
FROM
    TelldusActions
    INNER JOIN TelldusUnits ON TelldusActions.FK_TelldusUnit_Id = TelldusUnits.Id
    INNER JOIN TelldusActionTypes ON TelldusActions.FK_TelldusActionType_Id = TelldusActionTypes.Id
    INNER JOIN TelldusActionValues ON TelldusActions.FK_TelldusActionValue_Id = TelldusActionValues.Id
    INNER JOIN TelldusActionValueTypes ON TelldusActionValues.FK_TelldusActionValueType_Id = TelldusActionValueTypes.Id 
    INNER JOIN TelldusActionsPerformed ON TelldusActionsPerformed.FK_TelldusAction_Id = TelldusActions.Id
    WHERE TelldusUnits.Name IN ("Grovkök golvtermostat", "Huvudtermostat", "Uterum golvtermostat")
AND TelldusActionValueTypes.Name IN ("watt","temp")
GROUP BY TelldusUnits.Name,TelldusActionValues.ActionValue,TelldusActionValueTypes.Name
ORDER BY TelldusActionsPerformed.PerformedTime DESC

没错，如果想要最新时间，则需要添加一个不考虑TelldusActionsPerformed.PerformedTime的GROUPBY子句。请尝试此脚本
SELECT
    --TelldusActionsPerformed.PerformedTime AS TelldusActionsPerformed_PerformedTime,
    MAX(TelldusActionsPerformed.PerformedTime) AS TelldusActionsPerformed_PerformedTime,
    TelldusUnits.Name AS TelldusUnits_Name,
    TelldusActionValues.ActionValue AS TelldusActionValues_ActionValue,
    TelldusActionValueTypes.Name AS TelldusActionValueTypes_Name
FROM
    TelldusActions
    INNER JOIN TelldusUnits ON TelldusActions.FK_TelldusUnit_Id = TelldusUnits.Id
    INNER JOIN TelldusActionTypes ON TelldusActions.FK_TelldusActionType_Id = TelldusActionTypes.Id
    INNER JOIN TelldusActionValues ON TelldusActions.FK_TelldusActionValue_Id = TelldusActionValues.Id
    INNER JOIN TelldusActionValueTypes ON TelldusActionValues.FK_TelldusActionValueType_Id = TelldusActionValueTypes.Id 
    INNER JOIN TelldusActionsPerformed ON TelldusActionsPerformed.FK_TelldusAction_Id = TelldusActions.Id
    WHERE TelldusUnits.Name IN ("Grovkök golvtermostat", "Huvudtermostat", "Uterum golvtermostat")
AND TelldusActionValueTypes.Name IN ("watt","temp")
GROUP BY TelldusUnits.Name,TelldusActionValues.ActionValue,TelldusActionValueTypes.Name
ORDER BY TelldusActionsPerformed.PerformedTime DESC

工作答案
尽管Murillos没有回答我的问题（我仍然认为这是一个很好的答案），但我确实得到了帮助。这是我最后使用的问题，并且（希望）回答我最初的问题：
SELECT
    FROM_UNIXTIME(MAX(TelldusActionsPerformed.PerformedTime)) AS TelldusActionsPerformed_PerformedTime,
    TelldusUnits.Name AS TelldusUnits_Name,
    TelldusActionValues.ActionValue AS TelldusActionValues_ActionValue,
    TelldusActionValueTypes.Name AS TelldusActionValueTypes_Name
FROM
    TelldusActions
    INNER JOIN TelldusUnits ON TelldusActions.FK_TelldusUnit_Id = TelldusUnits.Id
    INNER JOIN TelldusActionTypes ON TelldusActions.FK_TelldusActionType_Id = TelldusActionTypes.Id
    INNER JOIN TelldusActionValues ON TelldusActions.FK_TelldusActionValue_Id = TelldusActionValues.Id
    INNER JOIN TelldusActionValueTypes ON TelldusActionValues.FK_TelldusActionValueType_Id = TelldusActionValueTypes.Id 
    INNER JOIN TelldusActionsPerformed ON TelldusActionsPerformed.FK_TelldusAction_Id = TelldusActions.Id
    WHERE TelldusUnits.Name IN ("Grovkök golvtermostat", "Huvudtermostat", "Uterum golvtermostat")
AND TelldusActionValueTypes.Name IN ("watt","temp")
GROUP BY TelldusUnits.Name, TelldusActionValues.ActionValue, TelldusActionValueTypes.Name
ORDER BY TelldusActionsPerformed.PerformedTime DESC

SELECT 
    OrderedResultSet.TelldusActionsPerformed_PerformedTime,
    OrderedResultSet.TelldusUnits_Name,
    OrderedResultSet.TelldusActionValues_ActionValue,
    OrderedResultSet.TelldusActionValueTypes_Name

FROM (
    SELECT
        FROM_UNIXTIME(MAX(TelldusActionsPerformed.PerformedTime)) AS TelldusActionsPerformed_PerformedTime,
        TelldusUnits.Name AS TelldusUnits_Name,
        TelldusActionValues.ActionValue AS TelldusActionValues_ActionValue,
        TelldusActionValueTypes.Name AS TelldusActionValueTypes_Name

    FROM
        TelldusActions
        INNER JOIN TelldusUnits ON TelldusActions.FK_TelldusUnit_Id = TelldusUnits.Id
        INNER JOIN TelldusActionTypes ON TelldusActions.FK_TelldusActionType_Id = TelldusActionTypes.Id
        INNER JOIN TelldusActionValues ON TelldusActions.FK_TelldusActionValue_Id = TelldusActionValues.Id
        INNER JOIN TelldusActionValueTypes ON TelldusActionValues.FK_TelldusActionValueType_Id = TelldusActionValueTypes.Id
        INNER JOIN TelldusActionsPerformed ON TelldusActionsPerformed.FK_TelldusAction_Id = TelldusActions.Id

    WHERE TelldusUnits.Name IN ("Grovkök golvtermostat", "Huvudtermostat", "Uterum golvtermostat")
        AND TelldusActionValueTypes.Name IN ("watt","temp")

    GROUP BY TelldusUnits.Name, TelldusActionValues.ActionValue, TelldusActionValueTypes.Name

    ORDER BY MAX(TelldusActionsPerformed.PerformedTime) DESC
) as OrderedResultSet

GROUP BY OrderedResultSet.TelldusUnits_Name, OrderedResultSet.TelldusActionValueTypes_Name

这为我提供了最佳结果（最新时间）：
有效答案
尽管Murillos没有回答我的问题（我仍然认为这是一个很好的答案），但我确实得到了帮助。这是我最后使用的问题，并且（希望）回答我最初的问题：
SELECT
    FROM_UNIXTIME(MAX(TelldusActionsPerformed.PerformedTime)) AS TelldusActionsPerformed_PerformedTime,
    TelldusUnits.Name AS TelldusUnits_Name,
    TelldusActionValues.ActionValue AS TelldusActionValues_ActionValue,
    TelldusActionValueTypes.Name AS TelldusActionValueTypes_Name
FROM
    TelldusActions
    INNER JOIN TelldusUnits ON TelldusActions.FK_TelldusUnit_Id = TelldusUnits.Id
    INNER JOIN TelldusActionTypes ON TelldusActions.FK_TelldusActionType_Id = TelldusActionTypes.Id
    INNER JOIN TelldusActionValues ON TelldusActions.FK_TelldusActionValue_Id = TelldusActionValues.Id
    INNER JOIN TelldusActionValueTypes ON TelldusActionValues.FK_TelldusActionValueType_Id = TelldusActionValueTypes.Id 
    INNER JOIN TelldusActionsPerformed ON TelldusActionsPerformed.FK_TelldusAction_Id = TelldusActions.Id
    WHERE TelldusUnits.Name IN ("Grovkök golvtermostat", "Huvudtermostat", "Uterum golvtermostat")
AND TelldusActionValueTypes.Name IN ("watt","temp")
GROUP BY TelldusUnits.Name, TelldusActionValues.ActionValue, TelldusActionValueTypes.Name
ORDER BY TelldusActionsPerformed.PerformedTime DESC

SELECT 
    OrderedResultSet.TelldusActionsPerformed_PerformedTime,
    OrderedResultSet.TelldusUnits_Name,
    OrderedResultSet.TelldusActionValues_ActionValue,
    OrderedResultSet.TelldusActionValueTypes_Name

FROM (
    SELECT
        FROM_UNIXTIME(MAX(TelldusActionsPerformed.PerformedTime)) AS TelldusActionsPerformed_PerformedTime,
        TelldusUnits.Name AS TelldusUnits_Name,
        TelldusActionValues.ActionValue AS TelldusActionValues_ActionValue,
        TelldusActionValueTypes.Name AS TelldusActionValueTypes_Name

    FROM
        TelldusActions
        INNER JOIN TelldusUnits ON TelldusActions.FK_TelldusUnit_Id = TelldusUnits.Id
        INNER JOIN TelldusActionTypes ON TelldusActions.FK_TelldusActionType_Id = TelldusActionTypes.Id
        INNER JOIN TelldusActionValues ON TelldusActions.FK_TelldusActionValue_Id = TelldusActionValues.Id
        INNER JOIN TelldusActionValueTypes ON TelldusActionValues.FK_TelldusActionValueType_Id = TelldusActionValueTypes.Id
        INNER JOIN TelldusActionsPerformed ON TelldusActionsPerformed.FK_TelldusAction_Id = TelldusActions.Id

    WHERE TelldusUnits.Name IN ("Grovkök golvtermostat", "Huvudtermostat", "Uterum golvtermostat")
        AND TelldusActionValueTypes.Name IN ("watt","temp")

    GROUP BY TelldusUnits.Name, TelldusActionValues.ActionValue, TelldusActionValueTypes.Name

    ORDER BY MAX(TelldusActionsPerformed.PerformedTime) DESC
) as OrderedResultSet

GROUP BY OrderedResultSet.TelldusUnits_Name, OrderedResultSet.TelldusActionValueTypes_Name

这为我提供了最佳结果（最新时间）：
谢谢你的帮助。我在ORDER BY
子句中得到一个奇怪的（？）行为。它似乎没有被考虑？哦，当然，我忘了在末尾添加MAX…ORDER BY MAX（TelldusActionsPerformed.PerformedTime）描述，它应该可以工作，欢迎你的帮助。我得到一个奇怪的（？）使用ORDER BY
子句的行为。它似乎没有被考虑？哦，当然，我忘了在末尾添加MAX…ORDER BY MAX（TelldusActionsPerformed.PerformedTime）DESC，它应该可以工作，您好