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JPA 实体综合指数收集
原标题:JPA entity composite index collection

我在我的项目中使用JPA +hibernate。 我不得不从已经存在的数据库中检索数据,不能对其作出修改。

The schema is like, there are multiple organizations, each company has many bills and each bill has many lineitems.

organization 
{

 id;

 name;

 ...
 }

bill 
{

   id;

   organization o;

   amount;

   ....

   (EAGER, mappedBy=bill)
   List<Lineitem> lineitems;
}


lineitem
{
     id;

     organization o;

     (EAGER)
     bill b;


     itemCode

     .....
}

The indexes in the database schema (currently present) bill table --> orgId (non unique index)

lineitem table --> orgId, billId

在要求一项法案时,它首先这样做。

Select *
from bills
where id = ?

这是罚款,因为它是关于主要钥匙的 f。 现在它搁置了各项目。

正在

select * from lineitems where billId = ?

数据库中没有账单指数。 同上。 orgId,bill有一个非独特的综合指数。 同上。

我必须做些什么,才能使用org的圆顶灯光灯。 同上。

select * from lineitems where billId = ? and orgId = ?

我不知道什么是合适的标题。

谢谢。

问题回答

它通过在账单实体中删除<代码>mappedBy=bill(关于细列项目清单),然后使用<代码>@joincolumns,以使用org_id和账单。





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