用idea搭建mybatis架构，简单的增删改

                                         Mybatis的搭建
1.持久化
  持久化，就是内存数据和硬盘数据状态的转换
 
2.ORM思想
Object Relation Mapping  对象关系映射
   
3.MyBatis入门案例

  3.1导入jar包
    依赖
  
   
      MySQL
      mysql-connector-java
      5.0.8
   

   
   
      org.mybatis
      mybatis
      3.2.2
   

  3.2书写大配置
 
 
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">

   
       
           
           
               
               
               
               
           
       
   
   
       
   

  3.3实体类（实体类的列必须和数据库的列一致）
     public class StudentInfo {
     private Integer stuId;
     private String stuName;
     private Integer  stuAge;
     private Date stuDate;
  }

  

小配置：

xml version="1.0" encoding="ISO-8859-1"?>

 mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="bdqn.dao.">
    <select id="select" resultType="bdqn.entity.Department">
 select * from department
    select>
    <select id="selectid" resultType="Department">
        select * from department where id=#{id}
    select>
mapper>

    4.大配置（resources）

               select * from studentinfo   

  两个注意事项：  1.你得更新POM.xml文件中build节点                    src/main/java                  **/*.xml                        2.你得在大配置中关联小配置文件      3.5 测试类

   

public class DepartmentTest {
    @Test
    public void show(){
        //查询列表
     /*   try {
            InputStream stream=Resources.getResourceAsStream("mybatis-config.xml.tld");
            SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(stream);
            SqlSession session=sqlSessionFactory.openSession();
            List list=session.selectList("select");
            for (Department item:list
                 ) {
                System.out.println(item.getName());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }*/
     //根据id查部门
        try {
            InputStream stream=Resources.getResourceAsStream("mybatis-config.xml.tld");
            SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(stream);
            SqlSession session=sqlSessionFactory.openSession();
            Department one=session.selectOne("selectid",1);
            System.out.println(one.getName());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }



}

            
 结论：
   1. 注意小配置的命名空间的名称
  

4.别名的使用 （加在大配置里）
   
       
       
       
   

小配置<select id="select" resultType="bdqn.entity.Department">改为

<select id="select" resultType="Department">

5.getMapper() 动态代理数据
  class 类型的类型
    is = Resources.getResourceAsStream(path);
            SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(is);
            SqlSession session=factory.openSession();
            IStudentInfoDAO dao = session.getMapper(IStudentInfoDAO.class);
            StudentInfo info = dao.getStudentById(3);
            System.out.println(info.getStuName());

增删该查接口：

增删在小配置里的写法：

//添加单测