我的查询出错了.为什么？我不明白:(
SELECT p.name,p.id,SUM(hours) AS hours,SUM(logged_hours) AS logged_hours
FROM (
SELECT project_id,date,hours,null AS logged_hours
FROM #{ScheduleEntry.table_name}
WHERE user_id = #{User.current.id}
AND date BETWEEN '%s' AND '%s'
UNION
SELECT project_id,spent_on AS date,null AS hours,sum(#{TimeEntry.table_name}.hours) AS logged_hours
FROM #{TimeEntry.table_name}
WHERE user_id = #{User.current.id}
AND spent_on BETWEEN '%s' AND '%s'
GROUP BY project_id,date
) AS results
LEFT JOIN #{Project.table_name} AS p ON p.id = results.project_id
GROUP BY project_id
将GROUP BY project_id更改为GROUP BY p.name,p.id
原文链接：https://www.f2er.com/postgresql/192210.htmlThe docs说：
When
GROUP BYis present,it is not valid for theSELECTlist expressions to refer to ungrouped columns except within aggregate functions,since there would be more than one possible value to return for an ungrouped column.
