MyBatis的基础方式的增删改查CRUD

配置基本信息：
详情

mybatis约定：
输入参数parameterType 和 输出参数resultType ，在形式上都只能有一个，所以有多个的时候要传对象

如果输入参数 ：是简单类型（8个基本类型+String） 是可以使用任何占位符,#{xxxx}
如果是对象类型，则必须是对象的属性 #{属性名}

输出参数： 如果返回值类型是一个 对象（如Student），则无论返回一个、还是多个，
在resultType都写成com.company.person
即 resultType=“com.company.person”

注意事项：
a如果使用的 事务方式为 jdbc,则需要 手工commit提交，即session.commit();
b所有的标签 等 ，都必须有sql语句，但是sql参数值可选
select* from student where stuno = #{xx}
sql有参数：session.insert(statement, 参数值 );

sql没参数：session.insert(statement);

personMapper.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:该mapper.xml映射文件的 唯一标识 -->
<mapper namespace="com.company.personMapper">
	
	 
	 
	<select id="queryPersonById" resultType="com.company.person" parameterType="int">
		select * from person where id=#{id}
	</select>
	
	<insert id="addPerson" parameterType="com.company.person">
		insert into person(id,name,age) values(#{id},#{name},#{age})
	</insert>
		 
	<update id="updatePerson" parameterType="com.company.person">
		update person set name=#{name},age=#{age} where id=#{id}
	</update>
	
	<delete id="deletePerson" parameterType="int">
		delete from person where id=#{id}
	
	</delete>
	
	<select id="queryAll" resultType="com.company.person">
		select * from person
	</select>
	
</mapper>

test.java

package com.company;
import java.util.List;
import java.io.IOException;
import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class test {
	//查询单个信息
	public static void queryPersonOne() throws IOException  {
		Reader reader = Resources.getResourceAsReader("conf.xml") ;
		SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader) ;
		SqlSession session = sessionFactory.openSession() ;
		String statement = "com.company.personMapper.queryPersonById" ;
		person person = session.selectOne( statement,2) ;
		System.out.println(person);
		session.close(); 
	}
	//查询全部信息
	public static void queryPersonAll() throws IOException  {
		Reader reader = Resources.getResourceAsReader("conf.xml") ;
		SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader) ;
		SqlSession session = sessionFactory.openSession() ;
		String statement = "com.company.personMapper."+"queryAll" ;
		List<person> pes=session.selectList(statement);
		System.out.println(pes);
		session.close(); 
	}
	//增加信息
	public static void AddPersonA() throws IOException  {
		Reader reader = Resources.getResourceAsReader("conf.xml") ;
		SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader) ;
		SqlSession session = sessionFactory.openSession() ;
		String statement = "com.company.personMapper.addPerson" ;
		person pe=new person(3,"cz",24);
		//statement:指定执行的sql
		//pe:sql中需要的参数
		int count=session.insert(statement,pe);
		session.commit();//提交事务
		System.out.println(count);
		session.close(); 
	}
	//删除信息
	public static void DeletePersonA() throws IOException  {
		Reader reader = Resources.getResourceAsReader("conf.xml") ;
		SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader) ;
		SqlSession session = sessionFactory.openSession() ;
		String statement = "com.company.personMapper.deletePerson" ;
		int num=session.delete(statement,3);
		session.commit();//提交事务
		System.out.println("删除"+num+"学生！！！！");
		session.close(); 
	}
	//修改信息
	public static void UpdatePersonA() throws IOException  {
		Reader reader = Resources.getResourceAsReader("conf.xml") ;
		SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader) ;
		SqlSession session = sessionFactory.openSession() ;
		String statement = "com.company.personMapper.updatePerson" ;
		//修改参数
		person pe=new person();
		//修改哪个人，where id=2;
		pe.setId(2);
		//修改成什么样子
		pe.setName("hah");
		pe.setAge(10);
		//执行
		int num=session.update(statement,pe);
		session.commit();
		System.out.println("修改"+num+"学生！！！！");
		session.close(); 
	}
	public static void main(String[] args) throws IOException{
		//AddPersonA();
		//DeletePersonA();
		UpdatePersonA();
		queryPersonAll();
		
	}
}