如何从Spring Data Repository接口方法@Query中的.properties文件中获取特定的属性值

问题描述

我能够在 Spring 类中获取属性值，如下所示:

I am able to get the property value in Spring classes like below:

@Value("${database.name}")
private String databaseName;

我必须通过连接不同数据库中的不同表来执行本机查询.

I have to execute a native query by joining different tables which are in different databases.

@Query(value="select t1.* FROM db1.table1 t1 INNER JOIN db2.table2 t2 ON t2.t1_id1 = t1.id1")

这里不是硬编码数据库名称，即 db1 和 db2，我必须从属性文件中获取它们.

Instead of hard coding database names i.e., db1 and db2 here, I have to get them from properties file.

如何获取Spring Data JPA Repository中@Query注解内的属性值?

how to get the property value inside the @Query annotation in Spring Data JPA Repository ?

推荐答案

不知道可不可以，如果不行，可以考虑这样的做法:

I don't know if it is possible, but if not, you can consider this approach:

您可以在查询中使用参数而不是直接使用 Repository 的 @Query 中的属性，但是当您调用实际方法时 - 您可以提供来自 .properties 的值.

Instead of using properties in Repository's @Query directly, you can use params in the query but when you call the actual method - you can provide values from .properties.

假设您有一个简单的存储库:

Imagine you have simple repository:

public interface UserRepository extends JpaRepository<User, Long> {

  // query with param
  @Query("select u from User u where u.lastname = :lastname")
  User findByLastname(@Param("lastname") String lastname);

}

然后，假设您有一些 Service 或 Controller 需要在其中使用 Repository - 您可以在那里注入属性并传递它们到您的方法:

Then, let's say you have some Service or Controller where you need to use your Repository - you can inject properties there and pass them to your method:

@Service
public class UserService {

    // this comes from .properties
    @Value("${user.lastName}")
    private String userLastName;

    @Autowired
    private UserRepository userRepository;

    public User getUser() {
        // you pass it as param to the repo method which
        // injects it into query
        return userRepository.findByLastname(userLastName);
    }
}

这只是一个例子.但我相信它可能有用.

This is just an example. But I believe it may be useful.

快乐黑客:)

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