MyBatis 基础配置【学习笔记 一】

学习能力强的建议查看官网学习：http://www.mybatis.org/mybatis-3/getting-started.html

创建Maven项目

Maven项目的创建查看此链接：https://blog.youkuaiyun.com/Kedongyu_/article/details/81365825

添加MyBatis相关类包

找到pom.xml，添加下列代码，保存：

		<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
		<dependency>
		    <groupId>org.mybatis</groupId>
		    <artifactId>mybatis</artifactId>
		    <version>3.4.6</version>
		</dependency>
				

创建config.xml文件

在Spring IoC容器配置文件同个目录下创建config.xml文件,并将下列内容粘贴到文件中，将数据库改为你所要连接的表，并修改账号密码。

<?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>
        <!-- Model类（表）别名 -->
	</typeAliases>

	<environments default="development">
		<environment id="development">
            <!-- 事务模式 -->
			<transactionManager type="JDBC" />
		    <!-- 连接池方式 -->
			<dataSource type="POOLED">
                <!-- 驱动 -->
				<property name="driver"	value="oracle.jdbc.driver.OracleDriver" />
                <!-- 数据库连接url -->
				<property name="url" value="${url}" />
                <!-- 账号 -->
				<property name="username" value="${user}" />
                <!-- 密码 -->
				<property name="password" value="${password}" />
			</dataSource>
		</environment>
	</environments>
	<mappers>
        <!-- 映射文件 -->

	</mappers>
</configuration>

到这里，MyBatis的基本配置已经完成，下面是一个小例子。

      1.修改配置文件，改为自己想要连接的数据库

      2.创建数据库表

oracle版本：

--创建学生表
create table Student(
    stuNo number,
    stuName varchar2(16),
    phone varchar2(11)
);
--序列
create sequence student_seq;

Mysql版本，使用Mysql的话，刚刚配置文件config.xml需要修改数据库驱动：

create table Student(
    stuNo number AUTO_INCREMENT,
    stuName varchar(16),
    phone varchar(11)
);

      3.创建对应的Model类：StudentModel.class，包路径为：com.example.model

public class StudentModel {
	private int stuNo;
	private String stuName;
	private String phone;
	public int getStuNo() {
		return stuNo;
	}
	public void setStuNo(int stuNo) {
		this.stuNo = stuNo;
	}
	public String getStuName() {
		return stuName;
	}
	public void setStuName(String stuName) {
		this.stuName = stuName;
	}
	public String getPhone() {
		return phone;
	}
	public void setPhone(String phone) {
		this.phone = phone;
	}
}

      4.创建dao层接口,包路径为：com.example.dao

public interface IStudentDao {
	//增加
	public void create(StudentModel student) throws Exception; 
	//删除
	public void delete(StudentModel student) throws Exception; 
	//修改
	public void update(StudentModel student) throws Exception; 
	//查询-全部
	public List<StudentModel> selectListByAll() throws Exception; 
}

      5.创建映射文件IStudentDaoMapper.xml,包路径：com.example.dao.mapper

其中:

namespace填映射的dao层接口（全路径，按Ctrl+鼠标轻触路径，路径出现下划线则说明是对的，下同）

id指的是对应的dao层接口里面定义的方法。

parameterType指的是方法传入参数类型

resultType指的是方法返回结果类型

<!DOCTYPE mapper
  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.dao.IStudentDao">
	<insert id="create"	parameterType="com.example.model.StudentModel">
		insert into Student(StuNo,StuName,Phone)
		values(Student_SEQ.nextval,#{stuName},#{phone})
	</insert>
	<update id="update" parameterType="com.example.model.StudentModel">
		update Student set StuName=#{stuName}, Phone=#{phone}
		where StuNo=#{stuNo}
	</update>
	<delete id="delete" parameterType="com.example.model.StudentModel">
		delete from HT_Neighbourhood where StuNo=#{stuNo}
	</delete>
	<!-- 查询-全部 -->
	<select id="selectListByAll" resultType="com.example.model.StudentModel">
		select * from Student
	</select>
</mapper>

      6.在MyBatis配置文件config.xml指定映射文件。

	<mappers>
        <!-- 映射文件 -->
		<mapper	resource="com/example/dao/mapper/IStudentDaoMapper.xml"/>	
	</mappers>

      6.创建测试文件：StudentDaoTest.class，包路径：com.example.test。

public class StudentDaoTest {

	public static final void main(String[] args) throws Exception{
		String resource = "config.xml";
		InputStream inputStream = Resources.getResourceAsStream(resource);
		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
		SqlSession session = sqlSessionFactory.openSession();
		IStudentDao studentDao=session.getMapper(IStudentDao.class);
		
		createTest(studentDao);
		session.commit();
		updateTest(studentDao);
		session.commit();
//		deleteTest(studentDao);
//		session.commit();
		toListByAllTest(studentDao);
		
		session.close();
	}
	
	public static void createTest(IStudentDao studentDao) throws Exception {
		StudentModel student=new StudentModel();
		student.setPhone("86110119120");
		student.setStuName("某某1号");
		studentDao.create(student);
		System.out.println("添加成功！");
	}
	public static void updateTest(IStudentDao studentDao) throws Exception{
		StudentModel student=new StudentModel();
		student.setPhone("86110119120");
		student.setStuName("某某2号");
		student.setStuNo(2);
		studentDao.create(student);
		System.out.println("修改成功！");
	}
	public static void deleteTest(IStudentDao studentDao) throws Exception{
		StudentModel student=new StudentModel();
		student.setStuNo(2);
		studentDao.delete(student);
		System.out.println("添加成功！");
	}
	public static void toListByAllTest(IStudentDao studentDao) throws Exception{
		List<StudentModel> list=studentDao.selectListByAll();
		System.out.println("查询成功！");
		for(StudentModel student:list) {
			System.out.println(student.getStuNo()+" "+student.getStuName()+" "+student.getPhone());
		}
	}
}

      6.以java Application方式执行测试文件。

控制台输出：

查看数据库：