JPA本机查询返回具有多个表的字段的实体 [英] JPA native query to return the entity with fields from multiple tables

问题描述

我在JPA NativeSql中有一个查询，在那里我做表和联接的联合。我创建了一个包含来自多个表的所有查询字段的实体。所以我不能像往常一样用JPA做@Column@ table。

I have a query in JPA NativeSql, where I do "unions" of tables and joins. I made an entity with all the query fields which are from multiple tables. So I can not do "@Column" "@ table" as usual with JPA.

我怎样才能将查询的给定值设置为我的实体？ / p>

How could I set the given values ​​of the query to my entity?

推荐答案

您可以使用 @SqlResultSetMapping 。

You can map the columns returned by your native SQL query to your entity by using @SqlResultSetMapping.

示例：

Query q = em.createNativeQuery(
    "SELECT o.id AS order_id, " +
        "o.quantity AS order_quantity, " +
        "o.item AS order_item, " +
        "i.name AS item_name, " +
    "FROM Order o, Item i " +
    "WHERE (order_quantity > 25) AND (order_item = i.id)",
    "OrderResults");

@SqlResultSetMapping(name="OrderResults", 
    entities={ 
        @EntityResult(entityClass=com.acme.Order.class, fields={
            @FieldResult(name="id", column="order_id"),
            @FieldResult(name="quantity", column="order_quantity"), 
            @FieldResult(name="item", column="order_item")
        })
    },
    columns={
        @ColumnResult(name="item_name")}
)

可以找到更多例子这里。

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