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我有一个骑自行车的数据库，我用它来学习使用 Libreoffice Base 和 HSQL 的 SQL。该数据库由一个表组成，其中包含以下列：索引、日期、自行车、里程。

我想做的是为我的公路自行车和我的 mtn 自行车创建一个列，其中包含每年的自行车骑行总和。我从子查询总和开始，但这给了我整个数据库的总数。这是我的公路自行车代码，另一个子查询将用于 mtn 自行车列：

SELECT YEAR( "RideDate" ) AS "Year", SUM( "Miles" ) AS "Miles", 
( SELECT SUM( "Miles" ) FROM "BikeDate" 
   WHERE( "Bike" = 'Fuji' OR "Bike" = 'Yfoil' )) AS "% Miles" 
FROM "BikeDate" AS "BikeDate" 
GROUP BY YEAR( "RideDate" ) 
ORDER BY YEAR( "RideDate" ) DESC

由于我按年份分组，我如何获得每个分组元素的总和 -> 年份？对于不知道正确的术语，我深表歉意。我也不想按年份分组和骑自行车做一个简单的总和，我有。我想使用 where 子句将年度总和分开。任何帮助表示赞赏，戴夫。LOBase 4.2.3.3 。

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让我根据您的实际需要提出两种可能性，以便返回原始帖子中的值：

SELECT 
   YEAR( "RideDate" ) AS "Year", 
   SUM( "Miles" ) AS "Miles", 
   SUM(CASE WHEN "Bike" = 'Fuji' OR "Bike" = 'Yfoil' THEN "Miles" ELSE 0 END) as "% Miles"
FROM "BikeDate" AS "BikeDate" 
GROUP BY YEAR( "RideDate" ) 
ORDER BY YEAR( "RideDate" ) DESC

为了创建一个额外的列，它真正计算 Percent 。. . 就像是：

SELECT 
   YEAR( "RideDate" ) AS "Year", 
   SUM( "Miles" ) AS "Miles", 
   SUM(CASE WHEN "Bike" = 'Fuji' OR "Bike" = 'Yfoil' THEN "Miles" ELSE 0 END) as "Miles_Fuji_Yfoil",
   SUM(CASE WHEN "Bike" = 'Fuji' OR "Bike" = 'Yfoil' THEN "Miles" ELSE 0 END) * 100.0000000 / SUM("Miles") as "Pct_Miles_Fuji_Yfoil"
FROM "BikeDate" AS "BikeDate" 
GROUP BY YEAR( "RideDate" ) 
ORDER BY YEAR( "RideDate" ) DESC

说明：这使用 HSQL 函数CASE WHEN。. . 或者 。. . value ELSE 0 END所以它只会对这些值求和（聚合函数）。

于 2014-07-15T14:55:41.537 回答