利用mybatis框架实现数据库表的CRUD

利用mybatis框架实现数据库表的CRUD

本文是基于Windows 10系统环境，利用mybatis框架实现数据库表的CRUD

• Windows 10
• IntelliJ

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一、构建过程（简单入门）

(1) 打开IntelliJ，创建一个新项目

(2) 选择“maven”工程，然后点击“next”

(3) 填写公司ID等信息，然后点击“next”

(4) 填写项目名称等信息，然后点击“finish”

(5) 点击“pom.xml”文件，然后填写各种依赖的坐标

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.inspur</groupId>
    <artifactId>day02_eesy_01mybatisCRUD</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
        </dependency>
    </dependencies>
</project>

(6) 创建一个User类，然后生成相应的属性和方法

package com.inspur.domain;

import java.io.Serializable;
import java.util.Date;

public class User implements Serializable{
    private Integer id;
    private String username;
    private Date birthday;
    private String sex;
    private String address;

    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 Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", birthday=" + birthday +
                ", sex='" + sex + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

(7) 创建一个QueryVo类，然后生成相应的属性和方法

package com.inspur.domain;

public class QueryVo {
    private User user;

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }
}

(8) 创建一个User类的持久层接口类

package com.inspur.dao;

import com.inspur.domain.User;
import com.inspur.domain.QueryVo;

import java.util.List;

public interface IUserDao {
    /**
     * 查询所有用户
     * @return
     */
    public List<User> findAll();

    /**
     * 保存用户
     * @param user
     */
    public void saveUser(User user);

    /**
     * 更新用户
     * @param user
     */
    public void updateUser(User user);

    /**
     * 删除用户
     * @param id
     */
    public void deleteUser(Integer id);

    /**
     * 通过id查询用户
     * @param id
     * @return
     */
    public User findById(Integer id);

    /**
     * 通过name模糊查询用户
     * @param username
     * @return
     */
    public List<User> findByName(String username);

    /**
     * 查询总个数
     * @return
     */
    public Integer findTotal();

    /**
     *
     * @param qv
     * @return
     */
    public List<User> findByQuery(QueryVo qv);
}

(9) 创建一个主配置文件SqlMapConfig.xml配置文件

<?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">
<!-- mybatis的主配置文件 -->
<configuration>
    <!-- 配置环境 -->
    <environments default="mysql">
        <!-- 配置mysql环境 -->
        <environment id="mysql">
            <!-- 配置事务类型 -->
            <transactionManager type="JDBC"></transactionManager>
            <!-- 配置数据源（连接池） -->
            <dataSource type="POOLED">
                <!-- 配置连接数据库的基本信息 -->
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://172.30.12.59:3306/eesy_mybatis"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    <!-- 指定映射配置文件的位置，映射配置文件指的是每个dao独立的配置文件 -->
    <mappers>
        <mapper resource="com/inspur/dao/IUserDao.xml"/>
    </mappers>
</configuration>

(10) 创建一个指定类IUserDao的配置文件IUserDao.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.inspur.dao.IUserDao">
    <!-- 查询所有 -->
    <select id="findAll" resultType="com.inspur.domain.User">
        select * from user
    </select>
    <!-- 保存用户 -->
    <insert id="saveUser" parameterType="com.inspur.domain.User">
        <!-- 配置插入操作，获取插入数据id -->
        <selectKey keyProperty="id" keyColumn="id" resultType="java.lang.Integer" order="AFTER">
            select last_insert_id()
        </selectKey>
        insert into user(username, address, sex, birthday) values(#{username}, #{address}, #{sex}, #{birthday})
    </insert>
    <!-- 更新用户 -->
    <update id="updateUser" parameterType="com.inspur.domain.User">
        update user set username=#{username},address=#{address},sex=#{sex},birthday=#{birthday} where id=#{id}
    </update>
    <!-- 删除用户 -->
    <delete id="deleteUser" parameterType="java.lang.Integer">
        delete from user where id=#{id}
    </delete>
    <!-- 通过id查询用户 -->
    <select id="findById" parameterType="java.lang.Integer" resultType="com.inspur.domain.User">
        select * from user where id=#{id}
    </select>
    <!-- 通过name模糊查询用户 -->
    <select id="findByName" parameterType="java.lang.String" resultType="com.inspur.domain.User">
        select * from user where username like #{name}
    </select>
    <!-- 查询总个数 -->
    <select id="findTotal" resultType="java.lang.Integer">
        select count(*) from user
    </select>
    <!-- 根据queryVo的条件查询用户 -->
    <select id="findByQuery" parameterType="com.inspur.domain.QueryVo" resultType="com.inspur.domain.User">
        select * from user where username like #{user.username}
    </select>
</mapper>

(11) 写一个测试类，测试CRUD结果

package com.inspur.test;
import java.io.InputStream;
import java.util.Date;
import java.util.List;
import com.inspur.dao.IUserDao;
import com.inspur.domain.User;
import com.inspur.domain.QueryVo;
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.After;
import org.junit.Before;
import org.junit.Test;

public class MybatisTest {
    private InputStream in;
    private SqlSession sqlSession;
    private IUserDao userDao;

    @Before
    public void init() throws Exception{
        //1.读取配置文件
        in = Resources.getResourceAsStream("SqlMapConfig.xml");
        //2.创建SqlSessionFactory工厂
        SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
        SqlSessionFactory factory = builder.build(in);
        //3.使用工厂生产SqlSession对象
        sqlSession = factory.openSession();
        //4.使用SqlSession对象创建Dao接口的代理对象
        userDao = sqlSession.getMapper(IUserDao.class);
    }

    @After
    public void destroy() throws Exception{
        sqlSession.commit();
        if(sqlSession != null)
            sqlSession.close();
        if(in != null)
            in.close();
    }

    /**
     * 测试查询所有操作
     * @throws Exception
     */
    @Test
    public void testFindAll() throws Exception{
        List<User> users = userDao.findAll();
        for (User user : users){
            System.out.println(user);
        }
    }

    /**
     * 测试保存操作
     * @throws Exception
     */
    @Test
    public void testSave() throws Exception{
        User user = new User();
        user.setUsername("李必");
        user.setAddress("山东");
        user.setSex("男");
        user.setBirthday(new Date());

        //5.使用代理对象执行方法
        userDao.saveUser(user);
        System.out.println(user);

    }

    /**
     * 测试更新操作
     * @throws Exception
     */
    @Test
    public void testUpdate() throws Exception{
        User user = new User();
        user.setId(50);
        user.setUsername("檀琪");
        user.setAddress("山东");
        user.setSex("女");
        user.setBirthday(new Date());

        //5.使用代理对象执行方法
        userDao.updateUser(user);
    }

    /**
     * 测试删除操作
     */
    @Test
    public void testDelete(){
        userDao.deleteUser(50);
    }

    /**
     * 测试通过id查询操作
     */
    @Test
    public void testFindById(){
        User user = userDao.findById(48);
        System.out.println(user);
    }

    /**
     * 测试通过name模糊查询操作
     */
    @Test
    public void testFindByName() throws Exception{
        String name = "老%";
        List<User> users = userDao.findByName(name);
        for (User user : users){
            System.out.println(user);
        }
    }

    /**
     * 测试查询总数操作
     */
    @Test
    public void testFindTotal(){
        Integer count = userDao.findTotal();
        System.out.println(count);
    }

    /**
     *
     */
    @Test
    public void testFindByQuery(){
        User user = new User();
        user.setUsername("%李%");

        QueryVo qv = new QueryVo();
        qv.setUser(user);

        List<User> users = userDao.findByQuery(qv);
        for (User u : users){
            System.out.println(u);
        }

    }
}

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