使用 Spring Data JDBC 和 CrudRepository 接口的多个数据源 [英] Multiple DataSources using Spring Data JDBC and CrudRepository Interface

问题描述

我有一个重要的问题:

我的案例:

• 使用Spring Data JDBC
• 使用两个数据库
• CrudRepository 的使用

正如您在 Spring 中看到的此处数据 JDBC 您可以扩展 CrudRepository 并使用 Spring 获得所有开箱即用的 Crud 操作 - 无需显式实现！

As you can see here in Spring Data JDBC you can extends CrudRepository and get with Spring all Crud Operations out of the box - without an explicit implementation!

这是一个简单的 4 步过程:

It's an easy 4 step process for:

1. 定义您的属性
2. 定义您的实体
3. 定义一个接口来扩展 CrudRepository 和
4. 使用该接口

但是在使用两个数据库的情况下，有一个 5. 步骤，您必须定义一个 @Configuration 类.

But in case of using two databases, there is a 5. Step in which you have to define a @Configuration class.

我做了以下 5 个步骤:

I did that these 5 steps as following:

 <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-jdbc</artifactId>
    </dependency>
    <dependency>
      <groupId>com.h2database</groupId>
      <artifactId>h2</artifactId>
      <scope>runtime</scope>
    </dependency>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <optional>true</optional>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
      <exclusions>
        <exclusion>
          <groupId>org.junit.vintage</groupId>
          <artifactId>junit-vintage-engine</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

1.定义您的属性

application.properties

## D1
datasource.db1.driverClassName=...
datasource.db1.username=...
datasource.db1.password=...
datasource.db1.jdbcUrl=...
## D2
datasource.db2.driverClassName=...
datasource.db2.username=...
datasource.db2.password=...
datasource.db2.jdbcUrl=...

2.定义您的实体(每个数据库一个)

Student.java//用于 db1

@Table("STUDENT_TABLE")
public class Student{
    @Id
    @Column("MAT_NR")
    private BigDecimal matNr;

    @Column("NAME")
    private String name;
}

Teacher.java//用于 db2

@Table("TEACHER_TABLE")
public class Teacher{
    @Id
    @Column("EMPLOYEE_NR")
    private BigDecimal employeeNr;

    @Column("NAME")
    private String name;
}

3.定义您的存储库(每个数据库一个)

StudentRepository.java//用于 DB1

@Repository
public interface StudentRepository extends CrudRepository<Student, BigDecimal> {}

TeacherRepository.java//用于 DB2

@Repository
public interface TeacherRepository extends CrudRepository<Teacher, BigDecimal> {}

4.定义你的@Configuration 类(每个数据库一个)

• 你也可以在一门课上同时参加这两个课程，但我是这样做的:

Db1Config.java

@Configuration
public class Db1Config {
    @Primary
    @Bean("db1DataSource")
    @ConfigurationProperties("datasource.db1")
    public DataSource db1DataSource() {
        return DataSourceBuilder.create().build();
    }
}

Db2Config.java

@Configuration
public class Db2Config {
    @Bean("db2DataSource")
    @ConfigurationProperties("datasource.db2")
    public DataSource db2DataSource() {
        return DataSourceBuilder.create().build();
    }
}

5.使用您的界面存储库

Application.java

@SpringBootApplication
public class Application implements CommandLineRunner {

    @Autowired @Qualifier("studentRepository") StudentRepository studentRepository
    @Autowired @Qualifier("teacherRepository") TeacherRepository teacherRepository 

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        studentRepository.findById(30688).ifPresent(System.out::println); // DB1
        teacherRepository.findById(5).ifPresent(System.out::println); // DB2
    }
}

这些工作正常！

导致错误:[...]: Unknown table name:TEACHER.

#回答前请注意:

这里我使用的是 Spring Data JDBC 而不是 Spring Data JPA.我知道它在 Spring Data JPA 中工作，就像这里描述的 https://www.baeldung.com/spring-data-jpa-multiple-databases.我也知道我可以使用这些 JdbcTemplate.但是那样的话，我必须自己编写这些 CRUD 操作，这些操作在 here 和这不是必需的.

Here i'm using Spring Data JDBC and not Spring Data JPA. I know that it works in Spring Data JPA like described here https://www.baeldung.com/spring-data-jpa-multiple-databases. I know also that i can make usage of these JdbcTemplate. But in that way, i have to write these CRUD Operations by myself which is described here and that’s not what need.

答案当然很好.

感谢您的帮助.

推荐答案

我遇到了类似的问题.根据 Chris Savory 的回答，我的解决方案必须将我的存储库放入 2 个单独的包中，然后定义 2 个 @Configuration 类，每个类定义 1 个 JdbcOperation.这是我的完整配置(我有一个 SQL Server 和一个 H2 数据源):

I had a similar problem. My solution had to have my repositories put in 2 separate packages, as per Chris Savory answer, and then define 2 @Configuration classes defining 1 JdbcOperation each. Here's my full configuration (I have an SQL Server and an H2 data sources):

application.properties

application.properties

请注意，这些属性是 Hikari CP 特定的.如果您选择不同的 CP(即 Tomcat)，里程可能会有所不同

## SQL SERVER DATA SOURCE
spring.sql-server-ds.jdbcUrl= jdbc:sqlserver://localhost:1554;databaseName=TestDB
spring.sql-server-ds.username= uteappl
spring.sql-server-ds.password= mypassword

## H2 DATA SOURCE
spring.h2-ds.jdbcUrl= jdbc:h2:mem:testdb;mode=MySQL
spring.h2-ds.username= sa
spring.h2-ds.password= password

第一个 H2 @Configuration

First H2 @Configuration

@Configuration
@EnableJdbcRepositories(jdbcOperationsRef = "h2JdbcOperations", basePackages = "com.twinkie.repository.h2")
public class H2JdbcConfiguration extends AbstractJdbcConfiguration {


  @Bean
  @ConfigurationProperties(prefix = "spring.h2-ds")
  public DataSource h2DataSource() {
    return DataSourceBuilder.create().build();
  }


  @Bean
  NamedParameterJdbcOperations h2JdbcOperations(@Qualifier("h2DataSource") DataSource sqlServerDs) {
    return new NamedParameterJdbcTemplate(sqlServerDs);
  }

  @Bean
  public DataSourceInitializer h2DataSourceInitializer(
      @Qualifier("h2DataSource") final DataSource dataSource) {
    ResourceDatabasePopulator resourceDatabasePopulator = new ResourceDatabasePopulator(
        new ClassPathResource("schema.sql"));
    DataSourceInitializer dataSourceInitializer = new DataSourceInitializer();
    dataSourceInitializer.setDataSource(dataSource);
    dataSourceInitializer.setDatabasePopulator(resourceDatabasePopulator);
    return dataSourceInitializer;
  }
}

第二个 SQL Server @Configuration

Second SQL Server @Configuration

@Configuration
@EnableJdbcRepositories("com.twinkie.repository.sqlserver")
public class SqlServerJdbcConfiguration {

  @Bean
  @Primary
  @ConfigurationProperties(prefix = "spring.sql-server-ds")
  public DataSource sqlServerDataSource() {
    return DataSourceBuilder.create().build();
  }

  @Bean
  @Primary
  NamedParameterJdbcOperations jdbcOperations(
      @Qualifier("sqlServerDataSource") DataSource sqlServerDs) {
    return new NamedParameterJdbcTemplate(sqlServerDs);
  }

}

然后我有我的存储库(请注意不同的包).

Then I have my repositories (please note the different packages).

SQL Server

package com.twinkie.repository.sqlserver;

import com.twinkie.model.SoggettoAnag;
import java.util.List;
import org.springframework.data.jdbc.repository.query.Query;
import org.springframework.data.repository.CrudRepository;

public interface SoggettoAnagRepository extends CrudRepository<SoggettoAnag, Long> {

  @Query("SELECT * FROM LLA_SOGGETTO_ANAG WHERE sys_timestamp > :sysTimestamp ORDER BY sys_timestamp ASC")
  List<SoggettoAnag> findBySysTimestampGreaterThan(Long sysTimestamp);
}

H2

package com.twinkie.repository.h2;

import com.twinkie.model.GlSync;
import java.util.Optional;
import org.springframework.data.jdbc.repository.query.Modifying;
import org.springframework.data.jdbc.repository.query.Query;
import org.springframework.data.repository.Repository;

public interface GlSyncRepository extends Repository<GlSync, String> {

  @Modifying
  @Query("INSERT INTO GL_SYNC (table_name, last_rowversion) VALUES (:tableName, :rowVersion) ON DUPLICATE KEY UPDATE last_rowversion = :rowVersion")
  boolean save(String tableName, Long rowVersion);

  @Query("SELECT table_name, last_rowversion FROM gl_sync WHERE table_name = :tableName")
  Optional<GlSync> findById(String tableName);
}

这篇关于使用 Spring Data JDBC 和 CrudRepository 接口的多个数据源的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！