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我使用休眠调用数据库

List<Object> result = session.openSession().createSQLQuery(myNativeSQLQuery).list();

不，我可以遍历该列表

Iterator iter = result.iterator();
while(iter.hasNext()){
    Object[] item = (Object[]) iter.next();
}

但是那个对象对我自己没有用，所以我想让那个对象映射到我实现的类上。

public class MyClass {

    private Long id;

    private String name

    private Set<MySecondClass> myList

    public void myFunc(){
        // do sth with that id or any other attribute mapped
    }   
}

我不想使用休眠注释和东西，因为定义的类将由定义本机 sql 查询的 xml 文件填充数据。这样，我想将生成的文档具体化到 mongodb 中以进行快速数据访问。

您在下面看到的此类 xml 文件的示例

<?xml version="1.0" encoding="UTF-8"?>
<mapping>
<resource>myResource</resource> <!-- the resource table in mysql where the base query is executed -->
<destination>myDestination</destination> <!-- the destination collection in mongodb -->

<document mapped="MyClass"> <!-- that docuemnt and the base query will be mapped on the class "MyClass"

    <base sql="select id, name from table1" />
    <reference id="_ID_" column="id" /> <!-- use the result from the base query and replace the placeholder _ID_ of all following sql querys with the value of id in that current iteration -->

    <lists>
        <myList mapped="MySecondClass" sql="select col1, col2 from table2 where referenceId=_ID_" /> <!-- each element of that listed will be mapped on MySecondClass and fills the property "myList"
    </lists>

</document>

4

1 回答 1

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结果是我不需要复制/映射对象。我只是可以使用注释org.springframework.data.mongodb.core.mapping.Document和来自 spring 数据的抽象类com.mongodb.BasicDBObject 。

@org.springframework.data.mongodb.core.mapping.Document
public class BasicDocument extends BasicDBObject {

}

之后我可以创建只是做

BasicDocument doc = new BasicDocument();
doc.put("key", "value");

并将该文档存储到 mongodb 中。这样我什至可以创建列表。

于 2012-10-16T09:38:45.363 回答