springboot怎么配置主从数据库

1、在application.properties中配置主数据源：

```properties

spring.datasource.url=jdbc:mysql://localhost:3306/main_db

spring.datasource.username=root

spring.datasource.password=password

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

```

2、在application.properties中配置从数据源：

```properties

spring.datasource.secondary.url=jdbc:mysql://localhost:3306/secondary_db

spring.datasource.secondary.username=root

spring.datasource.secondary.password=password

spring.datasource.secondary.driver-class-name=com.mysql.cj.jdbc.Driver

```

3、创建配置类来定义多数据源配置：

```java

@Configuration

public class DataSourceConfig {

@Primary

@Bean(name = "mainDataSource")

@ConfigurationProperties(prefix = "spring.datasource")

public DataSource mainDataSource() {

return DataSourceBuilder.create().build();

}

@Bean(name = "secondaryDataSource")

@ConfigurationProperties(prefix = "spring.datasource.secondary")

public DataSource secondaryDataSource() {

return DataSourceBuilder.create().build();

}

}

```

4、在Repository中指定数据源：

```java

@Repository

public class MainRepository {

@Autowired

@Qualifier("mainDataSource")

private DataSource dataSource;

// Repository methods

}

@Repository

public class SecondaryRepository {

@Autowired

@Qualifier("secondaryDataSource")

private DataSource dataSource;

// Repository methods

}

```

通过以上步骤，就可以在Spring Boot中配置主从数据库并在Repository中使用不同的数据源进行操作。