这一篇在上一篇的基础上简单讲解如何进行增删改查操作。
一、在mybatis的配置文件conf.xml中注册xml与注解映射
<!-- 注册映射文件 -->
<mappers>
<!-- 通过xml方式映射 -->
<mapper resource="com/mybatis/crud/userMapper.xml" />
<!-- 通过注解方式映射 -->
<mapper class="com.mybatis.crud.IUserMapper" />
</mappers>
二、在这个com.mybatis.crud包下面新建userMapper.xml文件与IUserMapper接口
1、userMapper.xml明细如下
<?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.mybatis.crud.userMapper">
<insert id="addUser" parameterType="com.mybatis.crud.User">
insert into users(id_id,name_n,age_a) values(#{id},#{name},#{age})
</insert>
<delete id="deleteUser" parameterType="int">
delete from users where
id_id=#{id}
</delete>
<update id="updateUser" parameterType="com.mybatis.crud.User">
update users set
name_n=#{name},age_a=#{age} where id_id =#{id}
</update>
<select id="getAllUsers" resultType="com.mybatis.crud.User"
resultMap="usermap">
select *
from Users
</select>
<resultMap type="com.mybatis.crud.User" id="usermap">
<id property="id" column="id_id" />
<result property="name" column="name_n" />
<result property="age" column="age_a" />
</resultMap>
<select id="getUser" parameterType="int" resultType="com.mybatis.crud.User"
resultMap="usermap">
select *
from Users where id_id=#{id}
</select>
</mapper>
2、IUserMapper接口定义如下
package com.mybatis.crud;
import java.util.List;
import java.util.Properties;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import org.apache.ibatis.type.JdbcType;
public interface IUserMapper {
@Insert("insert into users(id_id,name_n,age_a) values(#{id},#{name},#{age})")
public int add(User user);
@Delete("delete from users where id_id=#{id}")
public int deleteById(int id);
@Update("update users set name_n=#{name},age_a=#{age} where id_id =#{id}")
public int update(User user);
@Select("select * from Users where id_id=#{id}")
@Results({
@Result(property = "id", column = "id_id", jdbcType = JdbcType.INTEGER),
@Result(property = "name", column = "name_n", jdbcType = JdbcType.VARCHAR),
@Result(property= "age", column = "age_a", jdbcType = JdbcType.INTEGER) })
public User getById(int id);
@Select("select * from Users")
@Results({
@Result(property = "id", column = "id_id", jdbcType = JdbcType.INTEGER),
@Result(property = "name", column = "name_n", jdbcType = JdbcType.VARCHAR),
@Result(property= "age", column = "age_a", jdbcType = JdbcType.INTEGER) })
public List<User> getAll();
}
三、新建一个获取SqlSessionFactory的工具类
package com.mybatis.util;
import java.io.InputStream;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import com.mybatis.demo.test;
public class MybatisUtils {
public static SqlSessionFactory getFactory(){
String resource = "conf.xml";
InputStream inputStream = test.class.getClassLoader().getResourceAsStream(resource);
SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
return sessionFactory;
}
}
四、实际测试代码如下
package com.mybatis.crud;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.junit.Test;
import com.mybatis.util.MybatisUtils;
public class TestCrud {
//方法名称上面F11键 即可运行测试方法
@Test
public void testAdd() {
SqlSessionFactory factory = MybatisUtils.getFactory();
SqlSession session = factory.openSession(true);
String statement = "com.mybatis.crud.userMapper.addUser";
User user1 = new User();
user1.setId(199);
user1.setName("wrrrugggcj");
user1.setAge(296);
System.out.println("[xml]新增影响行数："+session.insert(statement, user1));
User user2 = new User();
user2.setId(198);
user2.setName("wrrrugggcjeee");
user2.setAge(26);
IUserMapper userMapper = session.getMapper(IUserMapper.class);
System.out.println("[注解]新增影响行数："+userMapper.add( user2));
session.close();
}
@Test
public void testUpdate() {
SqlSessionFactory factory = MybatisUtils.getFactory();
//默认手动提交
SqlSession session = factory.openSession();
String statement = "com.mybatis.crud.userMapper.updateUser";
User user1 = new User();
user1.setId(199);
user1.setName("199");
user1.setAge(89);
System.out.println("[xml]修改影响行数："+session.update(statement, user1));
User user2 = new User();
user2.setId(198);
user2.setName("198");
user2.setAge(89);
IUserMapper userMapper = session.getMapper(IUserMapper.class);
System.out.println("[注解]修改影响行数："+userMapper.update(user2));
//提交
session.commit();
session.close();
}
@Test
public void testDelete() {
SqlSessionFactory factory = MybatisUtils.getFactory();
SqlSession session = factory.openSession(true);
String statement = "com.mybatis.crud.userMapper.deleteUser";
System.out.println("[xml]删除影响行数："+session.delete(statement,199));
IUserMapper userMapper = session.getMapper(IUserMapper.class);
System.out.println("[注解]删除影响行数："+userMapper.deleteById(198));
session.close();
}
@Test
public void testGetAllusers() {
SqlSessionFactory factory = MybatisUtils.getFactory();
SqlSession session = factory.openSession(true);
String statement = "com.mybatis.crud.userMapper.getAllUsers";
List<User> users = session.selectList(statement);
System.out.println("[xml]查询用户列表："+users);
IUserMapper userMapper = session.getMapper(IUserMapper.class);
System.out.println("[注解]查询用户列表："+userMapper.getAll());
session.close();
}
}
至此，一个基于mybatis的简单增删改就完成了，不过建议在阅读这篇文章的时候先将入门篇看一遍就可以了。
时间： 2024-08-09 23:50:58