Hibernate SQL查询结果映射/转换到对象/类/ Bean [英] Hibernate SQL Query result Mapping/Convert TO Object/Class/Bean

问题描述

1 2：select（table。*）/（all column）is OK

  String sql =select t_student。 *来自t_student; 
 // String sql =select t_student.id，t_student.name，... from t_student; //选择所有列
 SQLQuery query = session.createSQLQuery（sql）; 
 query.addEntity（Student.class）; //或query.addEntity（alias，Student.class）; 
 //query.list（）; [Student @ ...，Student @ ...，Student @ ...] 
 query.setResultTransformer（Transformers.ALIAS_TO_ENTITY_MAP）; //或其他变换
 query.list（）; // [{Student（or alias）= Student @ ...}，{Student = Student @ ...}] 
  

3：选择一些列（不是全部），是错误

  String sql =select t_student。 id，t_student的t_student.name.t_student.sex; 
 SQLQuery query = session.createSQLQuery（sql）; 
 query.addEntity（Student.class）; 
 query.setResultTransformer（Transformers.ALIAS_TO_ENTITY_MAP）; 
 query.list（）; //例外：无效列/无列
  

我希望3能正常工作，结果可以映射到Student.class。

Like：Student [id = ?, name = ?, sex = ?,（其他字段为null / default）]

I'您可以进一步添加
.setResultTransformer（Transformers.aliasToBean（YOUR_DTO.class））;
并自动将其映射到您的自定义dto对象，另请参阅返回非托管实体。 $ b

例如：

  public List< MessageExtDto> getMessagesForProfile2（Long userProfileId）{
查询query = getSession（）。createSQLQuery（
 +从messageVO中选择a。*，b。*
 +作为
 +INNER JOIN（SELECT max（id）AS id，count（*）AS count FROM messageVO GROUP BY messageConversation_id）as b ON a.id = b.id
 +where a.id> 0 
 +）
 .addScalar（id，new LongType（））
 .addScalar（message，new StringType（））
 ..... ....你的映射
 .setResultTransformer（Transformers.aliasToBean（MessageExtDto.class））; 
 
列出< MessageExtDto> list = query.list（）; 
返回列表; 
} 
  

1 2: select (table.*)/(all column) is OK

String sql = "select t_student.* from t_student";
//String sql = "select t_student.id,t_student.name,... from t_student"; //select all column
SQLQuery query = session.createSQLQuery(sql);
query.addEntity(Student.class);//or query.addEntity("alias", Student.class);
//query.list();[Student@..., Student@..., Student@...]
query.setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP); //or other transformer
query.list(); //[{Student(or alias)=Student@...},{Student=Student@...}]

3: select some column(not all of), is Error

String sql = "select t_student.id,t_student.name.t_student.sex from t_student";
SQLQuery query = session.createSQLQuery(sql);
query.addEntity(Student.class);
query.setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP);
query.list(); //Exception:invalid column/no column

I want "3" to work ok, and let the result can be mapped to Student.class.
Like: Student[id=?, name=?, sex=?, (other field are null/default)]
I've no idea for this error, help me please!

解决方案

You can go further and add .setResultTransformer(Transformers.aliasToBean(YOUR_DTO.class)); and automatically map it to your custom dto object, see also Returning non-managed entities.

For example:

public List<MessageExtDto> getMessagesForProfile2(Long userProfileId) {
    Query query = getSession().createSQLQuery("  "
            + " select a.*, b.* "
            + " from messageVO AS a "
            + " INNER JOIN ( SELECT max(id) AS id, count(*) AS count FROM messageVO GROUP BY messageConversation_id) as b ON a.id = b.id "
            + " where a.id > 0 "
            + " ")
            .addScalar("id", new LongType())
            .addScalar("message", new StringType())
            ......... your mappings
            .setResultTransformer(Transformers.aliasToBean(MessageExtDto.class));

    List<MessageExtDto> list = query.list();
    return list;
}

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