mybatis知识总结

<!-- 映射 -->
  <resultMap id="userMap" type="User">
    <result column="id" property="id" />
    <result column="user_name" property="userName" />
    <result column="name" property="name" />
    <result column="age" property="age" />
    <result column="sex" property="sex" />
    <result column="password" property="password" />
    
</resultMap>
  <!--   这里使用的是resultMap,而不是resultType,
          id要保持一致;
  -->

    <select id="queryUserByUserName" resultMap="userMap">
        SELECT *, user_name userName  FROM tb_user WHERE user_name = #{userName}
    </select>


<!--     <select id="queryUserByUserName" resultType="com.j1.jdbc.Model.User"> -->
<!--         SELECT *, user_name userName  FROM tb_user WHERE user_name = #{userName} -->
<!-hui-     </select> -->

/*
Navicat MySQL Data Transfer

Source Server         : 127.0.0.1
Source Server Version : 50619
Source Host           : 127.0.0.1:3306
Source Database       : mybatis_test

Target Server Type    : MYSQL
Target Server Version : 50619
File Encoding         : 65001

Date: 2014-11-27 11:00:43
*/

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for tb_item
-- ----------------------------
DROP TABLE IF EXISTS `tb_item`;
CREATE TABLE `tb_item` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `item_name` varchar(32) NOT NULL COMMENT ‘商品名称‘,
  `item_price` float(6,1) NOT NULL COMMENT ‘商品价格‘,
  `item_detail` text COMMENT ‘商品描述‘,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of tb_item
-- ----------------------------
INSERT INTO `tb_item` VALUES (‘1‘, ‘iPhone 6‘, ‘5288.0‘, ‘苹果公司新发布的手机产品。‘);
INSERT INTO `tb_item` VALUES (‘2‘, ‘iPhone 6 plus‘, ‘6288.0‘, ‘苹果公司发布的新大屏手机。‘);

-- ----------------------------
-- Table structure for tb_order
-- ----------------------------
DROP TABLE IF EXISTS `tb_order`;
CREATE TABLE `tb_order` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` bigint(20) NOT NULL,
  `order_number` varchar(20) NOT NULL COMMENT ‘订单号‘,
  PRIMARY KEY (`id`),
  KEY `FK_orders_1` (`user_id`),
  CONSTRAINT `FK_orders_1` FOREIGN KEY (`user_id`) REFERENCES `tb_user` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of tb_order
-- ----------------------------
INSERT INTO `tb_order` VALUES (‘1‘, ‘1‘, ‘20140921001‘);
INSERT INTO `tb_order` VALUES (‘2‘, ‘2‘, ‘20140921002‘);
INSERT INTO `tb_order` VALUES (‘3‘, ‘1‘, ‘20140921003‘);

-- ----------------------------
-- Table structure for tb_orderdetail
-- ----------------------------
DROP TABLE IF EXISTS `tb_orderdetail`;
CREATE TABLE `tb_orderdetail` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `order_id` int(32) DEFAULT NULL COMMENT ‘订单号‘,
  `item_id` int(32) DEFAULT NULL COMMENT ‘商品id‘,
  `total_price` double(20,0) DEFAULT NULL COMMENT ‘商品总价‘,
  `status` int(11) DEFAULT NULL COMMENT ‘状态‘,
  PRIMARY KEY (`id`),
  KEY `FK_orderdetail_1` (`order_id`),
  KEY `FK_orderdetail_2` (`item_id`),
  CONSTRAINT `FK_orderdetail_1` FOREIGN KEY (`order_id`) REFERENCES `tb_order` (`id`),
  CONSTRAINT `FK_orderdetail_2` FOREIGN KEY (`item_id`) REFERENCES `tb_item` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of tb_orderdetail
-- ----------------------------
INSERT INTO `tb_orderdetail` VALUES (‘1‘, ‘1‘, ‘1‘, ‘5288‘, ‘1‘);
INSERT INTO `tb_orderdetail` VALUES (‘2‘, ‘1‘, ‘2‘, ‘6288‘, ‘1‘);
INSERT INTO `tb_orderdetail` VALUES (‘3‘, ‘2‘, ‘2‘, ‘6288‘, ‘1‘);
INSERT INTO `tb_orderdetail` VALUES (‘4‘, ‘3‘, ‘1‘, ‘5288‘, ‘1‘);

-- ----------------------------
-- Table structure for tb_user
-- ----------------------------
DROP TABLE IF EXISTS `tb_user`;
CREATE TABLE `tb_user` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `user_name` varchar(100) DEFAULT NULL COMMENT ‘用户名‘,
  `password` varchar(100) DEFAULT NULL COMMENT ‘密码‘,
  `name` varchar(100) DEFAULT NULL COMMENT ‘姓名‘,
  `age` int(10) DEFAULT NULL COMMENT ‘年龄‘,
  `sex` tinyint(1) DEFAULT NULL COMMENT ‘性别，1男性，2女性‘,
  `birthday` date DEFAULT NULL COMMENT ‘出生日期‘,
  `created` datetime DEFAULT NULL COMMENT ‘创建时间‘,
  `updated` datetime DEFAULT NULL COMMENT ‘更新时间‘,
  PRIMARY KEY (`id`),
  UNIQUE KEY `username` (`user_name`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of tb_user
-- ----------------------------
INSERT INTO `tb_user` VALUES (‘1‘, ‘zhangsan‘, ‘123456‘, ‘张三‘, ‘30‘, ‘1‘, ‘1984-08-08‘, ‘2014-09-19 16:56:04‘, ‘2014-09-21 11:24:59‘);
INSERT INTO `tb_user` VALUES (‘2‘, ‘lisi‘, ‘123456‘, ‘李四‘, ‘21‘, ‘2‘, ‘1991-01-01‘, ‘2014-09-19 16:56:04‘, ‘2014-09-19 16:56:04‘);
INSERT INTO `tb_user` VALUES (‘3‘, ‘wangwu‘, ‘123456‘, ‘王五‘, ‘22‘, ‘2‘, ‘1989-01-01‘, ‘2014-09-19 16:56:04‘, ‘2014-09-19 16:56:04‘);
INSERT INTO `tb_user` VALUES (‘4‘, ‘zhangwei‘, ‘123456‘, ‘张伟‘, ‘20‘, ‘1‘, ‘1988-09-01‘, ‘2014-09-19 16:56:04‘, ‘2014-09-19 16:56:04‘);
INSERT INTO `tb_user` VALUES (‘5‘, ‘lina‘, ‘123456‘, ‘李娜‘, ‘28‘, ‘1‘, ‘1985-01-01‘, ‘2014-09-19 16:56:04‘, ‘2014-09-19 16:56:04‘);
INSERT INTO `tb_user` VALUES (‘6‘, ‘lilei‘, ‘123456‘, ‘李磊‘, ‘23‘, ‘1‘, ‘1988-08-08‘, ‘2014-09-20 11:41:15‘, ‘2014-09-20 11:41:15‘);

package com.j1.mybatis.mapper;

import com.j1.mybatis.pojo.OrderUser;

public interface OrderMapper {
    /**
     * 根据订单编号查询订单信息和用户名,年龄
     * @param orderNum
     * @return
     */
    public OrderUser querOrderAndUserByOrderNum(String orderNum);

}

package com.j1.mybatis.mapper;

import static org.junit.Assert.*;

import java.io.IOException;
import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

import com.j1.mybatis.pojo.OrderUser;

public class OrderMapperTest {
    private OrderMapper orderMapper;

    @Before
    public void setUp() throws Exception {
        try {
            // 构造SqlSessionFactory
            // 定义配置文件路径
            String resource = "mybatis-config.xml";
            // 读取配置文件
            InputStream inputStream = Resources.getResourceAsStream(resource);
            // 通过SqlSessionFactoryBuilder构建一个SqlSessionFactory
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//            this.userDAO = new UserDao(sqlSessionFactory);
            SqlSession sqlSession = sqlSessionFactory.openSession(true);
            this.orderMapper=sqlSession.getMapper(OrderMapper.class);
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }

    @Test
    public void testQuerOrderAndUserByOrderNum() {
        OrderUser orderUser=orderMapper.querOrderAndUserByOrderNum("20140921002");
        System.out.println(orderUser);
    }

}

<?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.j1.mybatis.mapper.OrderMapper">
  
    <select id="querOrderAndUserByOrderNum" resultType="OrderUser">
            SELECT
            o.*,
            u.name,
            u.user_name,
            u.age
        FROM
            tb_order o
        LEFT JOIN tb_user u ON u.id = o.user_id
        WHERE
            o.order_number = #{orderNumber}
        
    </select>
    
</mapper>
  

<?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>
    <!-- 引入外部的配置文件 -->
    <properties resource="jdbc.properties"/>
    <settings>
        <!-- 开启驼峰自动映射 -->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
    <typeAliases>
        <!-- 设置别名 -->
        <!-- <typeAlias type="com.j1.Model.User" alias="User"/> -->
        <package name="com.j1.mybatis.pojo"/>
    </typeAliases>
    <!-- 指定环境 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.username}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
        <!-- 
        <environment id="test">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.test.driver}" />
                <property name="url" value="${jdbc.test.url}" />
                <property name="username" value="${jdbc.test.username}" />
                <property name="password" value="${jdbc.test.password}" />
            </dataSource>
        </environment>
         -->
    </environments>
    <mappers>
<!--          <mapper resource="UserMapper.xml" />  -->
<!--          <mapper resource="UserMapper2.xml" /> -->
<!--          <mapper class="com.j1.dao.IUser"/>  -->
        <!-- 配置掃描包 -->
         <package name="com.j1.mybatis.mapper"/> 
    </mappers>
</configuration>

@Test
    public void testQuerOrderAndUserByOrderNum2() {
        Order order=orderMapper.querOrderAndUserByOrderNum("20140921002");
        System.out.println(order);
    }

@Test
    public void queryOrderAndUserAndOrderDetailByOrderNumber() {
        Order order=orderMapper.queryOrderAndUserAndOrderDetailByOrderNumber("20140921002");
        System.out.println(order);
    }

<!-- 多对多 -->
    
    <resultMap type="Order" id="orderAndUserAndOrderDetailAndItemResultMap">
        <id property="id" column="id"/>
        <association property="user" javaType="User" autoMapping="true"/>
        
        <!-- 
            property: java对象中的属性名称
            javaType: 集合类型
            ofType： 集合中的元素的数据类型
         -->
        <collection property="orderdetails" javaType="List" ofType="Orderdetail" autoMapping="true">
            <id property="id" column="orderdetail_id"/>
            
            <!-- 完成 Item对象的映射 -->
            <association property="item" javaType="Item" autoMapping="true">
                <id property="id" column="item_id"/>
            </association>
        </collection>
    </resultMap>
    <select id="queryOrderAndUserAndOrderDetailAndItemByOrderNumber" resultMap="orderAndUserAndOrderDetailAndItemResultMap">
        SELECT
            o.*,
            u.name,
            u.user_name,
            u.age,
            od.id orderdetail_id,
          od.item_id,
            i.item_detail,
            i.item_name,
            i.item_price
        FROM
            tb_order o
        LEFT JOIN tb_user u ON u.id = o.user_id
        LEFT JOIN tb_orderdetail od ON od.order_id = o.id
        LEFT JOIN tb_item i ON i.id = od.item_id
        WHERE
            o.order_number = #{orderNumber}
    </select>

  /**
       * 多对多
     * 查询订单，查询出下单人信息并且查询出订单详情中的商品数据。
     * 
     * @param orderNumber
     * @return
     */
    public Order queryOrderAndUserAndOrderDetailAndItemByOrderNumber(String orderNum);

 /**
     * 多对多
     */
    @Test
    public void testQueryOrderAndUserAndOrderDetailAndItemByOrderNumber() {
        Order order = this.orderMapper.queryOrderAndUserAndOrderDetailAndItemByOrderNumber("20140921001");
        System.out.println(order);
    }