【Mybaits学习】05_ Mapping映射属性冲突

在实际开发中,字段名与实体类属性名不相同的问题,本章主要看一下解决方法

主要看第3个步骤中的操作说明,观察resultMap配置前后的结果

1、环境准备,建表

2、创建Pojo实体类,属性与数据库表中的column不一致

package nh.ui.automation.tools.Mybaits;

/**
 * 项目 ：UI自动化测试 Mybaits 类描述：
 * 
 * @author Eric
 * @date 2017年3月4日 nh.ui.automation.tools.Mybaits
 */
public class Order {
    private int id;
    private String orderNo;
    private float price;

    /**
     * 
     */
    public Order() {
        super();
    }

    /**
     * @param id
     * @param orderNo
     * @param price
     */
    public Order(int id, String orderNo, float price) {
        super();
        this.id = id;
        this.orderNo = orderNo;
        this.price = price;
    }

    /**
     * @return the id
     */
    public int getId() {
        return id;
    }

    /**
     * @param id
     *            the id to set
     */
    public void setId(int id) {
        this.id = id;
    }

    /**
     * @return the orderNo
     */
    public String getOrderNo() {
        return orderNo;
    }

    /**
     * @param orderNo
     *            the orderNo to set
     */
    public void setOrderNo(String orderNo) {
        this.orderNo = orderNo;
    }

    /**
     * @return the price
     */
    public float getPrice() {
        return price;
    }

    /**
     * @param price
     *            the price to set
     */
    public void setPrice(float price) {
        this.price = price;
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        return "Order [id=" + id + ", orderNo=" + orderNo + ", price=" + price + "]";
    }

}

3、创建mapper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="nh.ui.automation.tools.Mybaits.Order.orderMapper">
    <select id="getOrder" parameterType="int"
        resultType="nh.ui.automation.tools.Mybaits.Order">
        select * from orders where id=#{id}
    </select>

    <insert id="addOrder" parameterType="nh.ui.automation.tools.Mybaits.Order">
        insert into
        orders(order_no,order_price) values(#{orderNo},#{price})
    </insert>

    <select id="getAllOrder" resultType="nh.ui.automation.tools.Mybaits.Order"
        resultMap="orderResultMap">
        select * from orders
    </select>
    
//第一次测试代码时可以不引用resultMap,观察执行结果。
    <resultMap type="nh.ui.automation.tools.Mybaits.Order" id="orderResultMap">
        <id property="id" column="id" />
        <result property="orderNo" column="order_no" />
        <result property="price" column="order_price" />
    </resultMap>


</mapper>

4、在Mybaits配置文件中注册orderMapper文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <properties resource="db.properties"></properties>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${db.driver}" />
                <property name="url" value="${db.url}" />
                <property name="username" value="${db.username}" />
                <property name="password" value="${db.password}" />
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="Mappings/userMapper.xml"/>
        <mapper resource="Mappings/orderMapper.xml"/>
        <mapper class="nh.ui.automation.tools.mapper.UserMapper" />
    </mappers>
</configuration>

5、测试代码

        String statement = "nh.ui.automation.tools.Mybaits.Order.orderMapper.getOrder";
        Order order1 = sqlSession.selectOne(statement,1);
        System.out.println(order1);
        
        String statement1 = "nh.ui.automation.tools.Mybaits.Order.orderMapper.addOrder";
        int insert = sqlSession.insert(statement1,new Order(1,"dsf",11));
        System.out.println(insert);
        
        String statement2 = "nh.ui.automation.tools.Mybaits.Order.orderMapper.getAllOrder";
        
        List<Object> selectList = sqlSession.selectList(statement2);
        System.out.println(selectList);