mybatis一对多多对一

╰+哭是因爲堅強的太久メ 2022-07-21 01:52 209阅读 0赞

一、一对多：  
实体类

package com.ming.entity;
    
    import java.util.List;
    
    public class Station { 
        private String Sname;
        private String Sintroduction;
        private String Stel;
        private List<Staff> staffs;
    
        public String getSname() {
            return Sname;
        }
    
        public void setSname(String sname) {
            Sname = sname;
        }
    
        public String getSintroduction() {
            return Sintroduction;
        }
    
        public void setSintroduction(String sintroduction) {
            Sintroduction = sintroduction;
        }
    
        public String getStel() {
            return Stel;
        }
    
        public void setStel(String stel) {
            Stel = stel;
        }
    
        public List<Staff> getStaffs() {
            return staffs;
        }
    
        public void setStaffs(List<Staff> staffs) {
            this.staffs = staffs;
        }
    
        @Override
        public String toString() {
            return "Station [Sname=" + Sname + ", Sintroduction=" + Sintroduction + ", Stel=" + Stel + "]";
        }
    
    }

package com.ming.entity;
    
    public class Staff {
        private String staffNum;
        private String paswrod;
        private String conpany;
    
        public String getStaffNum() {
            return staffNum;
        }
    
        public void setStaffNum(String staffNum) {
            this.staffNum = staffNum;
        }
    
        public String getPaswrod() {
            return paswrod;
        }
    
        public void setPaswrod(String paswrod) {
            this.paswrod = paswrod;
        }
    
        public String getConpany() {
            return conpany;
        }
    
        public void setConpany(String conpany) {
            this.conpany = conpany;
        }
    
    }

mybatis 配置文件

<?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.ming.dao.StationDao">
        
        
        
        
        
        
        
        <resultMap type="Station" id="allStaff">
            
            <id column="Sname" property="Sname" />
            <result column="Sintroduction" property="Sintroduction" />
            <result column="Stel" property="Stel" />
            
            <collection property="staffs" column="Sname" ofType="Staff">
                <id column="staffNum" property="staffNum" />
                <result column="paswrod" property="paswrod" />
                <result column="conpany" property="conpany" />
            </collection>
        </resultMap>
    
        <select id="getAllStaff" resultMap="allStaff">
            select
            s.*,f.*
            from station
            s,staff f
            where s.Sname=f.conpany
            limit #{page.itemStart},
            #{page.pageSize}
    
        </select>
    
    </mapper>

二、多对一

package com.ming.entity;
    
    import java.util.Date;
    
    /** * Created by ming on 2016/7/8. */
    public class SuccessKilled { 
        private long seckillId;
        private long userPhone;
        private short state;
        private Date createTime;
        private Seckill seckill;
    
        public long getSeckillId() {
            return seckillId;
        }
    
        public void setSeckillId(long seckillId) {
            this.seckillId = seckillId;
        }
    
        public long getUserPhone() {
            return userPhone;
        }
    
        public void setUserPhone(long userPhone) {
            this.userPhone = userPhone;
        }
    
        public short getState() {
            return state;
        }
    
        public void setState(short state) {
            this.state = state;
        }
    
        public Date getCreateTime() {
            return createTime;
        }
    
        public void setCreateTime(Date createTime) {
            this.createTime = createTime;
        }
    
        public Seckill getSeckill() {
            return seckill;
        }
    
        public void setSeckill(Seckill seckill) {
            this.seckill = seckill;
        }
    
        @Override
        public String toString() {
            return "SuccessKilled{" +
                    "seckillId=" + seckillId +
                    ", userPhone=" + userPhone +
                    ", state=" + state +
                    ", createTime=" + createTime +
                    ", seckill=" + seckill +
                    '}';
        }
    }

package com.ming.entity;
    
    import java.util.Date;
    
    /** * Created by ming on 2016/7/8. */
    public class Seckill { 
    
        private long seckillId;
        private String name;
        private int number;
        private Date startTime;
        private Date endTime;
        private Date createTime;
    
        public long getSeckillId() {
            return seckillId;
        }
    
        public void setSeckillId(long seckillId) {
            this.seckillId = seckillId;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public int getNumber() {
            return number;
        }
    
        public void setNumber(int number) {
            this.number = number;
        }
    
        public Date getStartTime() {
            return startTime;
        }
    
        public void setStartTime(Date startTime) {
            this.startTime = startTime;
        }
    
        public Date getEndTime() {
            return endTime;
        }
    
        public void setEndTime(Date endTime) {
            this.endTime = endTime;
        }
    
        public Date getCreateTime() {
            return createTime;
        }
    
        public void setCreateTime(Date createTime) {
            this.createTime = createTime;
        }
    
        @Override
        public String toString() {
    
            return "Seckill{" +
                    "seckillId=" + seckillId +
                    ", name='" + name + '\'' +
                    ", number=" + number +
                    ", startTime=" + startTime +
                    ", endTime=" + endTime +
                    ", createTime=" + createTime +
                    '}';
        }
    }

<?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.ming.dao.SuccessKilledDao">
        <insert id="insertSuccessKilled">
            INSERT ignore INTO  success_killed (seckill_id,user_phone)
            VALUES (#{seckillId},#{userPhone})
        </insert>
    
        <select id="queryByIdWithSeckill" resultType="SuccessKilled">
            SELECT
            sk.seckill_id,
            sk.user_phone,
            sk.state,
            s.seckill_id "seckill.seckill_id",
            s.name "seckill.name",
            s.number "seckill.number",
            s.start_time "seckill.start_time",
            s.end_time "seckill.end_time",
            s.create_time "seckill.create_time"
    
            FROM success_killed sk INNER JOIN seckill s
            ON sk.seckill_id=s.seckill_id
            WHERE sk.seckill_id=#{seckillId}
    
        </select>
    
    </mapper>