hibernate - HQL 结合了“distinct”和“order by”

Question

如果我删除“distinct”或“order by”，则此查询有效，但它不能组合使用。我正在尝试遵循示例。你能解释一下吗？

String queryString = "select distinct event.county from Event as event order by event.county.county"

[main] - [ERROR] SqlExceptionHelper.logExceptions():144 >> ERROR: for SELECT DISTINCT, ORDER BY expressions must appear in select list
  Position: 215

生成的 SQL

select distinct county1_.Id as Id4_, county1_.County as County4_ from Event event0_ inner join County county1_ on event0_.CountyID=county1_.Id cross join County county2_ where event0_.CountyID=county2_.Id order by county2_.County 

Answer 1

尝试

select distinct county from Event event
inner join event.county county
order by county.county