mybatis--实现数据库增删改查

首先，创建一个数据库my，并在数据库中插入一张表user，然后在user表中插入一行数据，代码如下：

create database my;

use my;
create table user(
id int(10) auto_increment,
name varchar(64),
level varchar(256),
phone varchar(256),
primary key(id)
);

insert into user(id,name,level,phone) values(1,'a','a','1234555666');

其次，创建mybatis配置文件config.xml，配置文件代码如下：

<?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>
<typeAliases>
<typeAlias alias="User" type="com.zk.model.User" />
</typeAliases>

<environments default="development">
	<environment id="development">
		<transactionManager type="JDBC" />
		<dataSource type="POOLED">
		<property name="driver" value="com.mysql.jdbc.Driver" />
		<property name="url" value="jdbc:mysql://localhost:3306/my"/>
		<property name="username" value="root"/>
		<property name="password" value="123456"/>
		</dataSource>
	</environment>
</environments>

<mappers>
	<!-- // power by http://www.yiibai.com -->
	<mapper resource="com/zk/model/UserMapper.xml" />
</mappers>
</configuration>

再次，创建一个IUser.java接口

package com.zk.dao;

import java.util.List;

import com.zk.model.User;

public interface IUser {
	//增加
	public void addUser(User user);
	//删除
	public void deleteUser(int id);
	//更新
	public void updateUser(User user);
	//删除
	public User selectUser(int userid);
	//查看所有使用者
	public List<User> selectAllUser();
}

创建一个User.java实体类

package com.zk.model;

public class User {
	private int id;
	private String name;
	private String level;
	private String phone;
	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 getLevel() {
		return level;
	}
	public void setLevel(String level) {
		this.level = level;
	}
	public String getPhone() {
		return phone;
	}
	public void setPhone(String phone) {
		this.phone = phone;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", level=" + level
				+ ", phone=" + phone + "]";
	}
}

接着，在配置UserMapper.xml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="com.zk.dao.IUser">
    <insert id="addUser" parameterType="User">
  Insert into user(id,name,level,phone) values(#{id},#{name},#{level},#{phone});
    </insert>
    
    <delete id="deleteUser" parameterType="User">
    delete from user where id=#{id};
    </delete>
    
    <update id="updateUser" parameterType="User">
    update user set name=#{name},level=#{level},phone=#{phone} where id=#{id};
    </update>
    
    <select id="selectUser" parameterType="User" resultType="com.zk.model.User">
    Select * from user where id=#{id};
    </select>
    
    <select id="selectAllUser" resultType="com.zk.model.User">
    Select * from user;
    </select>
</mapper>

最后，构建一个Main.java，实现数据库增删改查的功能：

package MainApp;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

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 com.zk.dao.IUser;
import com.zk.model.User;

public class Main {
	private static SqlSessionFactory sqlsessionfactory;
	private static Reader reader;
	
	static{
		try {
			reader=Resources.getResourceAsReader("config/config.xml");
			sqlsessionfactory=new SqlSessionFactoryBuilder().build(reader);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public SqlSessionFactory getSqlSessionFactory()
	{
		return sqlsessionfactory;
	}
	
	public static void main(String[]args)
	{
		//Insert();
		//delete();
		//update();
		select(1);
	}
	
	public static void Insert(){
		//获取session连接
		SqlSession session=sqlsessionfactory.openSession();
		//获取mapper
		IUser usermap=session.getMapper(IUser.class);
		//执行插入
		User user1=new User();
		user1.setId(1);
		user1.setLevel("a");
		user1.setName("a");
		user1.setPhone("19832321123");
		usermap.addUser(user1);
		//提交事务
		//获取插入信息
		session.commit();
		selectAllUser();
	}

	public static void delete(){
		//获取session连接
		SqlSession session=sqlsessionfactory.openSession();
		//获取mapper
		IUser usermap=session.getMapper(IUser.class);
		//执行删除
		usermap.deleteUser(1);
		session.commit();
		selectAllUser();
	}
	
	public static void update(){
		//获取session连接
		SqlSession session=sqlsessionfactory.openSession();
		//获取mapper
		IUser usermap=session.getMapper(IUser.class);
		selectAllUser();
		User user = usermap.selectUser(1);
		user.setName("c");
		//执行删除
		usermap.updateUser(user);
		session.commit();
		selectAllUser();
	}
	
	public static void select(int id){
		//获取session连接
		SqlSession session=sqlsessionfactory.openSession();
		//获取mapper
		IUser usermap=session.getMapper(IUser.class);
		//selectAllUser();
		User user = usermap.selectUser(id);
		//执行查询
		System.out.println(user.toString());
		session.commit();
		//selectAllUser();
	}
	

	private static void selectAllUser() {
		// TODO Auto-generated method stub
		SqlSession session=sqlsessionfactory.openSession();
		IUser user=session.getMapper(IUser.class);
		printUser(user.selectAllUser());
	}

	private static void printUser(final List<User> users) {
		// TODO Auto-generated method stub
		int count = 0;

        for (User user : users) {
            System.out.println("User Id: " + user.getId());
            System.out.println("User Name: " + user.getName());
            System.out.println("User Dept: " + user.getLevel());
            System.out.println("User Website: " + user.getPhone());
        }
	}
}

这样就完成了数据库的增删改查。

程序结构如下图所示：