HQL結合了「distinct」和「order by」

Question

如果我刪除「distinct」或「order by」，但它不起作用，此查詢將起作用。我試圖遵循例子。你能解釋一下嗎？

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

嘗試用

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