Mybatis的增删改查

Mybatis的增删改查

• UserDao

public interface UserDao {
    //查询全部用户
    List<User> getUserList();
    //根据ID查询用户
    User getUserById(int id);
    //insert一个用户
    int addUser(User user);
    //修改用户
    int updateUser(User user);
    //删除用户
    int deleteUser(int id);
}

• UserMapper

<?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.sun.dao.UserDao">
    <select id="getUserList" resultType="com.sun.pojo.User">
        select * from mybatis.user
    </select>
    <select id="getUserById" parameterType="int" resultType="com.sun.pojo.User">
        select * from mybatis.user where id = #{id}
    </select>
    <insert id="addUser" parameterType="com.sun.pojo.User">
        insert into mybatis.user(id,name,pwd) values (#{id},#{name},#{pwd});
    </insert>
    <update id="updateUser" parameterType="com.sun.pojo.User">
        update mybatis.user set name=#{name},pwd=#{pwd} where id =#{id};
    </update>
    <delete id="deleteUser" parameterType="int">
        delete from mybatis.user where id = #{id};
    </delete>
</mapper>

• User

public class User {
    private int id;
    private String name;
    private String pwd;

    public User() {
    }

    public User(int id, String name, String pwd) {
        this.id = id;
        this.name = name;
        this.pwd = pwd;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pwd='" + pwd + '\'' +
                '}';
    }
}

• UserDaoTest

public class UserDaoTest {
    @Test
   public void test(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        List<User> userList = userDao.getUserList();
        for (User user : userList){
            System.out.println(user);
        }
        sqlSession.close();
    }
    @Test
    public void getUserById(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        User user = mapper.getUserById(3);
        System.out.println(user);
        sqlSession.close();
    }
    @Test
    public void addUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
       UserDao mapper = sqlSession.getMapper(UserDao.class);
       int res = mapper.addUser(new User(4,"哈哈","123456789"));
       if(res>0){
           System.out.println("插入成功");
       }
       sqlSession.commit();
       sqlSession.close();
    }
    @Test
    public void updateUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        mapper.updateUser(new User(4,"呵呵","123321"));
        sqlSession.commit();
        sqlSession.close();
    }
    @Test
    public void deleteUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        mapper.deleteUser(4);
        sqlSession.commit();
        sqlSession.close();
    }
}