<!-- Calcite 核心依賴 -->
<dependency>
    <groupId>org.apache.calcite</groupId>
    <artifactId>calcite-core</artifactId>
    <version>1.36.0</version> 
</dependency>
<!-- MySQL 適配器（用于適配 MySQL 數(shù)據(jù)源） -->
<dependency>
    <groupId>org.apache.calcite</groupId>
    <artifactId>calcite-mysql</artifactId>
    <version>1.36.0</version>
</dependency>
<!-- MongoDB 適配器（用于適配 MongoDB 數(shù)據(jù)源） -->
<dependency>
    <groupId>org.apache.calcite</groupId>
    <artifactId>calcite-mongodb</artifactId>
    <version>1.36.0</version>
</dependency>
<!-- Spring Boot 與 MyBatis Plus 集成核心依賴 -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.5.5</version> <!-- 適配 Spring Boot 3 的穩(wěn)定版 -->
</dependency>
<!-- 數(shù)據(jù)庫連接池依賴（MyBatis Plus 需連接池支持） -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.2.20</version>
</dependency>

{
  "version": "1.0",
  "defaultSchema": "ecommerce",
  "schemas": [
    {
      "name": "ecommerce",
      "type": "custom",
      "factory": "org.apache.calcite.adapter.jdbc.JdbcSchema$Factory",
      "operand": {
        "jdbcUrl": "jdbc:mysql://localhost:3306/ecommerce_order?useSSL=false&serverTimezone=UTC",
        "username": "root",
        "password": "123456",
        "driver": "com.mysql.cj.jdbc.Driver"
      }
    },
    {
      "name": "user_mongo",
      "type": "custom",
      "factory": "org.apache.calcite.adapter.mongodb.MongoSchema$Factory",
      "operand": {
        "host": "localhost",
        "port": 27017,
        "database": "user_db",
        "collection": "user_info"
      }
    }
  ]
}

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.autoconfigure.ConfigurationCustomizer;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.apache.calcite.jdbc.CalciteConnection;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.DriverManager;
import java.util.Properties;
@Configuration
// MyBatis Plus  mapper 接口掃描（指定 mapper 包路徑）
@MapperScan(basePackages = "com.example.calcite.mapper")
public class CalciteMybatisPlusConfig {
    // 1. 配置 Calcite 數(shù)據(jù)源（核心，與原邏輯一致）
    @Bean
    public DataSource calciteDataSource() throws Exception {
        Properties props = new Properties();
        props.setProperty("model", "classpath:calcite-model.json");
        Connection connection = DriverManager.getConnection("jdbc:calcite:", props);
        CalciteConnection calciteConnection = connection.unwrap(CalciteConnection.class);
        return calciteConnection.getDataSource();
    }
    // 2. 配置 MyBatis Plus 的 SqlSessionFactory，指定使用 Calcite 數(shù)據(jù)源
    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSource calciteDataSource) throws Exception {
        MybatisSqlSessionFactoryBean sessionFactory = new MybatisSqlSessionFactoryBean();
        // 注入 Calcite 數(shù)據(jù)源
        sessionFactory.setDataSource(calciteDataSource);
        // 配置 mapper.xml 文件路徑（如果使用 XML 方式編寫 SQL）
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath:mapper/*.xml"));
        // 配置 MyBatis Plus 全局參數(shù)（可選）
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true); // 下劃線轉(zhuǎn)駝峰
        sessionFactory.setConfiguration(configuration);
        // 注入 MyBatis Plus 插件（如分頁插件）
        sessionFactory.setPlugins(mybatisPlusInterceptor());
        return sessionFactory.getObject();
    }
    // 3. MyBatis Plus 分頁插件（可選，復(fù)雜查詢分頁用）
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL)); // 適配 Calcite 兼容的 MySQL 語法
        return interceptor;
    }
    // 4. 配置事務(wù)管理器（可選，需要事務(wù)支持時添加）
    @Bean
    public PlatformTransactionManager transactionManager(DataSource calciteDataSource) {
        return new DataSourceTransactionManager(calciteDataSource);
    }
}

import lombok.Data;
@Data
public class UserOrderVO {
    private String orderId;      // 訂單 ID（來自 MySQL）
    private String orderTime;    // 下單時間（來自 MySQL）
    private BigDecimal amount;   // 訂單金額（來自 MySQL）
    private String userName;     // 用戶名（來自 MongoDB）
    private String phone;        // 手機號（來自 MongoDB）
    private String userId;       // 用戶 ID（關(guān)聯(lián)字段）
}

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import java.util.List;
// 繼承 BaseMapper，獲得 MyBatis Plus 基礎(chǔ) CRUD 能力
public interface UserOrderMapper extends BaseMapper<UserOrderVO> {
    // 注解方式編寫跨數(shù)據(jù)源關(guān)聯(lián) SQL
    @Select("SELECT " +
            "o.order_id AS orderId, o.order_time AS orderTime, o.amount, " +
            "u.user_name AS userName, u.phone, o.user_id AS userId " +
            "FROM ecommerce.order o " +  // ecommerce：MySQL 的 Schema；order：訂單表
            "JOIN user_mongo.user_info u " +  // user_mongo：MongoDB 的 Schema；user_info：用戶表
            "ON o.user_id = u.user_id " +
            "WHERE o.user_id = #{userId}")
    List<UserOrderVO> queryUserOrderByUserId(@Param("userId") String userId);
}

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserOrderServiceImpl extends ServiceImpl<UserOrderMapper, UserOrderVO> implements UserOrderService {
    @Override
    public List<UserOrderVO> getUserOrderByUserId(String userId) {
        // 調(diào)用 Mapper 接口方法，實現(xiàn)跨數(shù)據(jù)源查詢
        return baseMapper.queryUserOrderByUserId(userId);
        // 若使用 XML 方式：return baseMapper.queryUserOrderByUserIdWithXml(userId);
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController
public class CrossDataSourceQueryController {
    @Autowired
    private UserOrderService userOrderService;
    @GetMapping("/user/order/{userId}")
    public List<UserOrderVO> queryUserOrder(@PathVariable String userId) {
        // 調(diào)用 Service 方法，返回跨數(shù)據(jù)源查詢結(jié)果
        return userOrderService.getUserOrderByUserId(userId);
    }
}