mybatis 1对多

待我称王封你为后i 2022-03-10 05:24 153阅读 0赞

**pojo**

> **private List<Orders> orders;**

public class User implements Serializable {
    	/**
    	 * 
    	 */
    	private static final long serialVersionUID = 1L;
    	private Integer id;
    	private String username;
    	private String sex;
    	private Date birthday;
    	private String address;
    
    	private List<Orders> orders;
    
    	
    	
    	public List<Orders> getOrders() {
    		return orders;
    	}
    	public void setOrders(List<Orders> orders) {
    		this.orders = orders;
    	}
    	public Integer getId() {
    		return id;
    	}
    	public void setId(Integer id) {
    		this.id = id;
    	}
    	public String getUsername() {
    		return username;
    	}
    	public void setUsername(String username) {
    		this.username = username;
    	}
    	public String getSex() {
    		return sex;
    	}
    	public void setSex(String sex) {
    		this.sex = sex;
    	}
    	public Date getBirthday() {
    		return birthday;
    	}
    	public void setBirthday(Date birthday) {
    		this.birthday = birthday;
    	}
    	public String getAddress() {
    		return address;
    	}
    	public void setAddress(String address) {
    		this.address = address;
    	}
    	@Override
    	public String toString() {
    		return "User [id=" + id + ", username=" + username + ", sex=" + sex
    				+ ", birthday=" + birthday + ", address=" + address + "]";
    	}
    
    	
    	
    
    }

**mapper.xml**

<resultMap type="com.it.mybatis.pojo.User" id="userOrderResultMap">
    		<id property="id" column="id" />
    		<result property="username" column="username" />
    		<result property="birthday" column="birthday" />
    		<result property="sex" column="sex" />
    		<result property="address" column="address" />
    
    		
    		<collection property="orders" ofType="com.it.mybatis.pojo.Orders">
    			
    			<id property="id" column="oid" />
    			<result property="number" column="number" />
    			<result property="createtime" column="createtime" />
    			<result property="note" column="note" />
    		</collection>
    	</resultMap>
    
    	
    	<select id="queryUserOrder" resultMap="userOrderResultMap">
    		SELECT
    		u.id,
    		u.username,
    		u.birthday,
    		u.sex,
    		u.address,
    		o.id oid,
    		o.number,
    		o.createtime,
    		o.note
    		FROM
    		`user` u
    		LEFT JOIN `orders` o ON u.id = o.user_id
    	</select>