Java jpa本机查询控制实体（第2部分）

续

• 我的数据库（测试）
  

• 首先，我想备份

  company

  表

  String query = "SELECT c.ID as companyid, c.name as companyname FROM company c";
  Query q = em.createNativeQuery(query, "MAPPING");
  List<CompanyDTO> list = q.getResultList();
  
  Company.java
  @SqlResultSetMapping(name = "MAPPING", classes = {
  @ConstructorResult(
      targetClass = CompanyDTO.class,
      columns = {
          @ColumnResult(name = "companyid"),
          @ColumnResult(name = "companyname")
      })
  })
  ...
  

  String query = "SELECT s.ID as staffid, s.name as staffname, s.companyID as companyID 
                  FROM staff s JOIN company c ON c.ID = s.companyID";
  Query q = em.createNativeQuery(query, "MAPPING");
  List<CompanyDTO> list = q.getResultList();
  
  Company.java
  @SqlResultSetMapping(name = "MAPPING", classes = {
  @ConstructorResult(
      targetClass = CompanyDTO.class,
      columns = {
          @ColumnResult(name = "staffid"),
          @ColumnResult(name = "staffname"),
          @ColumnResult(name = "companyID")
      })
  })
  ...
  

• 现在我不想修理我的桌子和教室。我该如何控制这个过程？从以下几点

  SELECT ... FROM ? 
  List<?> list = q.getResultList();
  

  选择。。。从…起
  List List=q.getResultList（）；
  

  需要帮忙吗

---

您的JDBC驱动程序是否支持在SELECT via参数中指定表？因为不是所有的文件你都能给我提供一个简单的例子让我明白？明白什么？您说过要发出类似“SELECT…FROM？”的SQL查询，因此可能希望将表名作为JDBC参数。我问，你的JDBC驱动程序支持吗？是的。我是用mysql驱动的。

SELECT ... FROM ? 
List<?> list = q.getResultList();