14-整合Mybaits数据库

整合Mybaits数据库(重点)

1. 导包

    <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.0</version>
        </dependency>

2.配置文件

• application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?serverTimeZone=UTC&useUnicode=true&characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

#整合mybaits
mybatis.type-aliases-package=com.tian.pojo
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml

3.UserMapper

package com.tian.mapper;

import com.tian.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

//也可以在启动类用@MapperScan("com.tian.mapper")
@Mapper
@Repository //把他放在spring
public interface UserMapper {

    List<User> queryList();

    User queryUserById(int id);

    int addUser(User user);

    int updateUser(User user);

    int deleteUser(int id);
}

4.UserMapper.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">
<!--namespace 绑定一个对应的dao/mapper文件-->
<mapper namespace="com.tian.mapper.UserMapper">

  <select id="queryList" resultType="User">
select  * from user
  </select>

    <select id="queryUserById" resultType="User">
       select  * from user  where id=#{id}
    </select>

    <insert id="addUser" parameterType="User">
        insert into user (id,name,pwd) values(#{id},#{name},#{pwd})
    </insert>

    <update id="updateUser" parameterType="User">
        update user set name=#{name},pwd=#{pwd} where id=#{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        delete  from user where id=#{id}
    </delete>


</mapper>

5.serivce层调用dao层 (略过)

6.controller层调用service层

package com.tian.controller;

import com.tian.mapper.UserMapper;
import com.tian.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {
    @Autowired
    private UserMapper userMapper;
@GetMapping("queryList")
    public List<User> queryList(){
        List<User> userList=userMapper.queryList();
//        for (User user:
//             userList) {
//            System.out.println(user);
//        }
        return userList;
    }

    //添加一个用户
    @GetMapping("/addUser")
    public String addUser(){
    userMapper.addUser(new User(6,"阿毛","456465"));
    return "ok";
    }

    //修改一个用户
    @GetMapping("/updateUser")
    public String updateUser(){
        userMapper.updateUser(new User(6,"小阿毛","456465"));
        return "ok";
    }
    //根据id删除用户
    @GetMapping("/deleteUser")
    public String deleteUser(){
        userMapper.deleteUser(6);
        return "ok";
    }
}

包结构