使用 HSQL 和 WHERE 语句时的问题答案

【问题标题】：Issues when using HSQL and WHERE statement使用 HSQL 和 WHERE 语句时的问题
【发布时间】：2021-01-25 10:55:43
【问题描述】：

在 HSQL 中使用 WHERE 语句时遇到问题。当我输入如下代码时，我没有收到任何错误：

"SELECT Year, ProjectName, (cast(sum(Missed) as float)/(select cast(sum(d.Missed) as float) from Draft d)) as MissedPer from Draft group by ProjectName, Year order by ProjectName"

但是，当我在嵌套查询中添加 WHERE 语句时，出现错误：

"SELECT Year, ProjectName, (cast(sum(Missed) as float)/(select cast(sum(d.Missed) as float) from Draft d where Year = '19.12')) as MissedPer from Draft group by ProjectName, Year order by ProjectName"

错误如下：

线程“main”中的异常 java.sql.SQLSyntaxErrorException：表达式不在聚合或 GROUP BY 列中：语句 [SELECT BranchNo, CAST(( SUM(PUBLIC.DRAFT.MISSED)) AS DOUBLE)/(()) ProjectName, (cast(sum(Missed) as float)/(select cast(sum(d.Missed) as float) from Draft d where d.BranchNo = '19.12')) as MissedPer from Draft group by ProjectName, BranchNo order by项目名称]

我不知道该怎么做，请帮忙。

【问题讨论】：

标签： hsqldb

【解决方案1】：

我检查了 HSQLDB 2.5.1 版本，查询返回结果：

create table draft (year varchar(10), projectname varchar (10), missed int);
insert into draft values '19.10', 'p alpha', 10
insert into draft values '19.11', 'p alpha', 12
insert into draft values '19.12', 'p alpha', 3


YEAR  PROJECTNAME MISSEDPER          
----- ----------- ------------------ 
19.10 p alpha     3.3333333333333335 
19.11 p alpha     4.0                
19.12 p alpha     1.0

【讨论】：