在hql中左连接第一个匹配

Question

select 
    schedulingpool.id,
    schedulingpool.allocationVersion,
    schedulingpool.tx.statusId,
    schedulingpool.name,
    schedulingpool.description,
    schedulingpool.schedulingPoolAddresses.name,
    schedulingpool.schedulingPoolAddresses.zip,
    schedulingpool.schedulingPoolAddresses.city,
    schedulingpool.schedulingPoolAddresses.countryId,
    schedulingpool.schedulingPoolAddresses.street,
    schedulingpool.statusId,
    schedulingpool.tx.name,
    schedulingpool.note1,
    schedulingpool.note2
from 
    com.xx.module.mm.jpa.SchedulingPool as schedulingpool 
left join schedulingpool.tx
left join schedulingpool.schedulingPoolAddresses
where schedulingpool.clientId = :clientId
     order by schedulingpool.id DESC

  

javax.servlet.ServletException：java.lang.IllegalArgumentException：   org.hibernate.QueryException：非法尝试取消引用   集合[scheduling0_.id.schedulingPoolAddresses]与元素   属性引用[name]

调度池可以有多个地址，当我执行语句时，我得到了异常。 有没有办法只获取匹配的第一个地址并加入它以防止此异常？

Answer 1

您需要使用别名

select 
    schedulingpool.id,
    schedulingpool.allocationVersion,
    tx.statusId,
    schedulingpool.name,
    schedulingpool.description,
    schedulingPoolAddresses.name,
    schedulingPoolAddresses.zip,
    schedulingPoolAddresses.city,
    schedulingPoolAddresses.countryId,
    schedulingPoolAddresses.street,
    schedulingpool.statusId,
    tx.name,
    schedulingpool.note1,
    schedulingpool.note2
from 
    com.xx.module.mm.jpa.SchedulingPool as schedulingpool 
left join schedulingpool.tx tx
left join schedulingpool.schedulingPoolAddresses schedulingPoolAddresses
where schedulingpool.clientId = :clientId
     order by schedulingpool.id DESC

您需要在SchedulingPool课程中与schedulingPoolAddresses和tx建立关联。