跳到主要内容

3. Mybatis增删改查

接口代码:

和之前操作数据库dao层接口是一样的

package com.neu.dao;

import com.neu.pojo.User;

import java.util.List;

public interface UserMapper {

/**
* 查询所有User
* @return List<User>
*/
List<User> getUserList();

/**
* 通过id查询User
* @param id
* @return int
*/
User getUserById(int id);

/**
* 插入User
* @param user
* @return int
*/
int addUser(User user);

/**
* 修改User
* @param user
* @return int
*/
int updateUser(User user);

/**
* 通过id删除User
* @param id
* @return int
*/
int deleteUser(int id);
}

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UserDao/UserMapper-->
<mapper namespace="com.neu.dao.UserMapper">
<!--select id="绑定的dao接口中的方法名"-->
<select id="getUserList" resultType="com.neu.pojo.User">
select * from user
</select>

<!--通过id查询-->
<select id="getUserById" parameterType="int" resultType="com.neu.pojo.User">
select * from user where id = #{id}
</select>

<!--增-->
<insert id="addUser" parameterType="com.neu.pojo.User">
insert into user values (#{id},#{name},#{pwd})
</insert>

<!--改-->
<update id="updateUser" parameterType="com.neu.pojo.User">
update user set name = #{name} ,pwd = #{pwd} where id = #{id}
</update>

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

测试代码:

image-20200606151531321