MyBatis------3.MyBatis實現數據庫的增刪改查（接口方式）

一.項目結構圖

二.pom.xml，數據庫表的結構，Student實體類同上篇文章

三.定義StudentDao接口，定義操作數據庫的方法

package cn.bd.dao;

import java.util.List;

import org.apache.ibatis.annotations.Param;

import cn.bd.domain.Student;

public interface StudentDao {
	//查詢
	List<Student> getAllStudent();//查找所有學生信息
	Student getStudent(int id);//查找指定id信息
	List<Student> getStudentByCity(String city);//按城市查找
	List<Student> getStudentByName(@Param("name")String name);
	Student getStudentByIdName(@Param("id")int id,@Param("name")String name);
	
	
	int addStudent(Student stu);
	int deleteStudent(int id);
	int update(Student stu);
	

}

四.在實現StudentDao接口前，需要建立mybatis-config.xml配置文件

<?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>
	<properties resource="db.properties"/>
		
	<environments default="development">
		<environment id="development">
			<transactionManager type="JDBC" />
			<dataSource type="POOLED">
				<property name="driver" value="${driverClass}" />
				<property name="url" value="${url}" />
				<property name="username" value="${username}" />
				<property name="password" value="${password}" />
			</dataSource>
		</environment>
	</environments>
	<mappers>
		<mapper resource="mapper.xml" />
	</mappers>
</configuration>

配置文件中引入了外部文件db.properties

driverClass=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8
username=root
password=123456

五.定義mapper.xml配置文件，實現StudentDao接口（底層原理，動態代理）

<?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="cn.bd.dao.StudentDao">
  
  <select id="getAllStudent" resultType="cn.bd.domain.Student">
    select * from student
  </select>
  
  <select id="getStudent" resultType="cn.bd.domain.Student">
    select * from student where id=#{id}
  </select>
  
    <select id="getStudentByCity" resultType="cn.bd.domain.Student">
    select * from student where city=#{city}
  </select>
  
  <select id="getStudentByName" resultType="cn.bd.domain.Student" >
  		select * from student where name like '%${name}%'
  </select>
  
  <select id="getStudentByIdName" resultType="cn.bd.domain.Student">
  		select * from student where id=#{id} and name like '%${name}%' 
  </select>
  
  <insert id="addStudent" parameterType="cn.bd.domain.Student">
  	insert into student(id,name,city,age) values(null,#{name},#{city},#{age})
  </insert>
  
  <delete id="deleteStudent" parameterType="int">
  	delete from student where id=#{id}
  </delete>
  
  <update id="update" parameterType="cn.bd.domain.Student">
  	update student set name=#{name},city=#{city},age=#{age} 
  				   where id=#{id} 
  </update>
  
  
</mapper>

六.添加測試類

package cn.bd.test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

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

import cn.bd.dao.StudentDao;
import cn.bd.domain.Student;
import junit.framework.TestCase;

public class Test extends TestCase {
	
	StudentDao studentDao;
	SqlSession session;
	{
		String resource = "mybatis-config.xml";
		InputStream inputStream;
		try {
			inputStream = Resources.getResourceAsStream(resource);
			SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
			session = sqlSessionFactory.openSession();
			studentDao=session.getMapper(StudentDao.class);
			
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
	
	public void getAllStudent(){
		List<Student> list=studentDao.getAllStudent();
		for (Student student : list) {
			System.out.println(student);
		}
	}
	
	public void getStudent(){
		System.out.println(studentDao.getStudent(2));;
	}
	
	public void getStudentByName(){
		List<Student> list=studentDao.getStudentByName("xiao");
		for (Student student : list) {
			System.out.println(student);
		}
	}
	
	public void getStudentByIdName(){
		Student list=studentDao.getStudentByIdName(3, "xiao");
		System.out.println(list);
	}
	
	public void testadd() {
		Student stu=new Student();
		stu.setAge(5);
		stu.setCity("aa");
		stu.setName("xiaoming");
		studentDao.addStudent(stu);
		session.commit();
	}
	
	public void deleteStu() {
		studentDao.deleteStudent(16);
		session.commit();
	}
	
	public void testupdate() {
		Student stu=new Student();
		stu.setId(12);
		stu.setAge(5);
		stu.setCity("aa");
		stu.setName("xiaomin");
		studentDao.update(stu);
		session.commit();
	}
	
	public void getStudentByCity(){
		List<Student> list=studentDao.getStudentByCity("北京");
		for (Student student : list) {
			System.out.println(student);
		}
	}
	
}