mybatis的一对一与一对多

冷不防 2024-03-22 18:43 84阅读 0赞

我现在有两个表，是一对多的关系，CREATE TABLE `repayment_plan` (  
，针对一个还款计划可多次进行还款'; 下面请帮我映射成两个bean对象

ID bigint(20) NOT NULL COMMENT '主键',
    CONSUMER_ID bigint(20) DEFAULT NULL COMMENT '发标人用户标识',
    USER_NO varchar(50) DEFAULT NULL COMMENT '发标人用户编码',
    PROJECT_ID bigint(20) DEFAULT NULL COMMENT '标的标识',
    PROJECT_NO varchar(50) DEFAULT NULL COMMENT '标的编码',
    NUMBER_OF_PERIODS int(11) DEFAULT NULL COMMENT '期数',
    INTEREST decimal(10,2) DEFAULT NULL COMMENT '还款利息',
    PRINCIPAL decimal(10,2) DEFAULT NULL COMMENT '还款本金',
    AMOUNT decimal(10,2) DEFAULT NULL COMMENT '本息',
    SHOULD_REPAYMENT_DATE datetime DEFAULT NULL COMMENT '应还时间',
    REPAYMENT_STATUS varchar(50) DEFAULT NULL COMMENT '应还状态0.待还,1.已还， 2.部分还款',
    CREATE_DATE datetime DEFAULT NULL COMMENT '计划创建时间',
    COMMISSION decimal(10,2) DEFAULT NULL COMMENT '年化利率(平台佣金，利差)',
    PRIMARY KEY (ID)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='借款人还款计划';
    
    CREATE TABLE repayment_detail (
    ID bigint(20) NOT NULL COMMENT '主键',
    REPAYMENT_PLAN_ID bigint(20) DEFAULT NULL COMMENT '还款计划项标识',
    AMOUNT decimal(10,2) DEFAULT NULL COMMENT '实还本息',
    REPAYMENT_DATE datetime DEFAULT NULL COMMENT '实际还款时间',
    REQUEST_NO varchar(50) DEFAULT NULL COMMENT '冻结用户资金请求流水号(用于解冻合并整体还款)，
    STATUS tinyint(4) DEFAULT NULL COMMENT '可用状态',
    PRIMARY KEY (ID)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='借款人还款明细

以下是对应的Java Bean对象：

1.  RepaymentPlan.java

import java.math.BigDecimal;
    import java.time.LocalDateTime;
    
    public class RepaymentPlan {
    
        private Long id;
    
        private Long consumerId;
    
        private String userNo;
    
        private Long projectId;
    
        private String projectNo;
    
        private Integer numberOfPeriods;
    
        private BigDecimal interest;
    
        private BigDecimal principal;
    
        private BigDecimal amount;
    
        private LocalDateTime shouldRepaymentDate;
    
        private String repaymentStatus;
    
        private LocalDateTime createDate;
    
        private BigDecimal commission;
    
        // getter 和 setter 略
    }

1.  RepaymentDetail.java

import java.math.BigDecimal;
    import java.time.LocalDateTime;
    
    public class RepaymentDetail {
    
        private Long id;
    
        private Long repaymentPlanId;
    
        private BigDecimal amount;
    
        private LocalDateTime repaymentDate;
    
        private String requestNo;
    
        private Integer status;
    
        // getter 和 setter 略
    }

我所使用的是mybatisPlus,我想查询RepaymentPlanDTO,这个DTO有一个属性List<RepaymentDetailDTO>, 一对多， java代码如何实现

好的，如果使用MybatisPlus，则需要先定义对应的MybatisPlus相关的Mapper接口和XML文件，考虑到你的需求，以下是对应的Mapper和XML的代码示例：

1.  RepaymentPlanMapper.java

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    
    public interface RepaymentPlanMapper extends BaseMapper<RepaymentPlan> {
        
        // 定义方法查询RepaymentPlanDTO及对应的RepaymentDetailDTO列表
        List<RepaymentPlanDTO> selectRepaymentPlanWithDetail();
    }

1.  repayment\_plan.xml

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
    
    <mapper namespace="com.example.mapper.RepaymentPlanMapper">
    
        <resultMap id="repaymentPlanResultMap" type="com.example.dto.RepaymentPlanDTO" >
            
            <id property="id" column