Mybatis

 

01.书写大配置：

mybatis-config.xml,并将大配置放在src目录下：

<?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">
<!-- root Node -->
<configuration>
   <!--别名定制-->
   <typeAliases>
       <typeAlias type="cn.happy.entity.Dept" alias="Dept"/>
   </typeAliases>
    <environments default="development">
    <!-- only One  db environment -->
        <environment id="development">
          <!-- tx use jdbc's  -->
            <transactionManager type="managed" />
            <!-- datasource's type is pooled 
               it can use the value of list:
               pooled
               unpooled
               jndi
            -->
            <dataSource type="UNPOOLED">
                <property name="driver" value="oracle.jdbc.OracleDriver" />
                <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" ></property>
                <property name="username" value="dog" />
                <property name="password" value="dog" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="cn/happy/entity/Dept.xml" />
        <mapper resource="cn/happy/entity/GetMapper.xml" />
    </mappers>
</configuration>

02.书写实体类：

package cn.happy.entity;

public class Dept {
  private Integer deptno;
      private String deptname;

    public Integer getDeptno() {
        return deptno;
    }
    public void setDeptno(Integer deptno) {
        this.deptno = deptno;
    }
    public String getDeptname() {
        return deptname;
    }
    public void setDeptname(String deptname) {
        this.deptname = deptname;
    }
  
}

03.书写小配置（包含crud）

<?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:隔离同名类 -->
<mapper namespace="cn.happy.entity.Dept">
    <select id="selectDept" resultType="Dept">
     <!-- SQL  列名，表名和数据库表 不区分大小写
               记录是区分的:  oa  OA
      -->
        select * from Dept
    </select>
    
    <!-- 1.1 带条件查询 -->
    <select id="selectDeptById" parameterType="Dept" resultType="Dept">
       select * from Dept where deptno=#{deptno}
    </select>

    <!-- 1.2 insert -->
    <insert id="insertDept" parameterType="Dept">
       insert into Dept(deptno,deptname) values(#{deptno},#{deptname})
    </insert>
    
    
    <!-- 1.2 update -->
    <update id="updateDeptById" parameterType="Dept">
       update Dept set deptname=#{deptname} where deptno=#{deptno}
    </update>
    
    
    <!-- 1.3 delete-->
    <delete id="deleteDeptById" parameterType="Dept">
       delete from Dept where deptno=#{deptno}
    </delete>
</mapper>

04.测试类

package cn.happy.test;
//ALt+/   

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.Reader;
import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

import cn.happy.dao.IDeptDao;
import cn.happy.entity.Dept;

public class H_01Test {
    /**
     * 1.5 getMapper()
     * @throws FileNotFoundException 
     * @throws Exception
     */
    @Test
    public  void testgetAllDepts() throws Exception{
        //通过session的getMapper(传入接口类型的字节码)返回的是一个接口类型的对象
        IDeptDao mapper = session.getMapper(IDeptDao.class);
        //通过接口类型的对象中自己定制的方法，可以得到想要的结果
        try {
            List<Dept> list = mapper.getAllDepts();
            for (Dept dept : list) {
                System.out.println(dept.getDeptname());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        
    }
    
    
    
    
    
    /**
     * 1.1 delete
     * @throws FileNotFoundException 
     * @throws Exception
     */

    @Test
    public  void testdeleteDeptById() throws Exception{
        Dept dt=new Dept();
        dt.setDeptno(32);
        int count = session.delete("deleteDeptById",dt);
        session.commit();
        System.out.println(count);
        session.close();
    }
    
    
    
    /**
     * 1.1 update
     * @throws FileNotFoundException 
     * @throws Exception
     */

    @Test
    public  void testupdateDeptById() throws Exception{
        Dept dt=new Dept();
        dt.setDeptno(1);
        dt.setDeptname("月饼不");
        int count = session.update("updateDeptById",dt);
        session.commit();
        System.out.println(count);
        session.close();
    }
    
    /**
     * 1.1 insert
     * @throws FileNotFoundException 
     * @throws Exception
     */
    
    @Test
    public  void testinsertDept() throws Exception{
        Dept dt=new Dept();
        dt.setDeptname("月饼兔子");
        dt.setDeptno(54);
        int count = session.insert("insertDept",dt);
        session.commit();
        System.out.println(count);
        session.close();
    }

    /**
     * 1.1 带条件查询
     * @throws FileNotFoundException 
     * @throws Exception
     */
    
    @Test
    public  void testselectDeptById() throws Exception{
        Dept dt=new Dept();
        dt.setDeptno(1);
        Dept dept = session.selectOne("selectDeptById",dt);
        System.out.println(dept.getDeptname());
        session.close();
    }
    
    
    
    
    
    
    
    
    SqlSession session;
    @Before
    public void initData() throws FileNotFoundException{
              //1.1 SqlSessionFactoryBuilder
                SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
                
                //1.2 SqlSesssionFactory
                Reader reader=new FileReader("src/mybatis-config.xml");
                SqlSessionFactory factory = builder.build(reader);
                
                //1.3  SqlSession
                session= factory.openSession();
    }
    
    
    
    
    @Test
    public  void testselectDept() throws Exception{
        //1.1 SqlSessionFactoryBuilder
        SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
        
        //1.2 SqlSesssionFactory
        Reader reader=new FileReader("src/mybatis-config.xml");
        SqlSessionFactory factory = builder.build(reader);
        
        //1.3  SqlSession
        SqlSession session = factory.openSession();
        List<Dept> list = session.selectList("selectDept");
        for (Dept dept : list) {
            System.out.println(dept.getDeptname());
        }
        session.close();
    }
}

别名的使用（如下实体类就可以用Dept代替）

<!--别名定制-->
   <typeAliases>
       <typeAlias type="cn.happy.entity.Dept" alias="Dept"/>
   </typeAliases>

GetMapper()的使用

首先创建接口：IDeptDao

package cn.happy.dao;

import java.util.List;

import cn.happy.entity.Dept;

/**
 * 接口
 * @author Happy
 * 该接口有对应的xml文件
 *
 */
public interface IDeptDao {
   //部门中的数据进行CRUD操作
   //检索所有部门
    public List<Dept> getAllDepts();
}

然后创建该接口对应的xml文件，相当于把实体类里边的方法描述在了xml文件中：

<?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">
<!-- 相当与getMapper的映射文件 mapper里边有命名空间-->
<mapper namespace="cn.happy.dao.IDeptDao">
<select id="getAllDepts" resultType="Dept">
select * from dept
</select>
</mapper>

 书写测试类：

    /**
     * 1.5 getMapper()
     * @throws FileNotFoundException 
     * @throws Exception
     */
    @Test
    public  void testgetAllDepts() throws Exception{
        //通过session的getMapper(传入接口类型的字节码)返回的是一个接口类型的对象
        IDeptDao mapper = session.getMapper(IDeptDao.class);
        //通过接口类型的对象中自己定制的方法，可以得到想要的结果
            List<Dept> list = mapper.getAllDepts();
            for (Dept dept : list) {
                System.out.println(dept.getDeptname());
            }
        
        
        
    }
    
    
    

    /**
     * 1.5 getMapper()
     * @throws FileNotFoundException 
     * @throws Exception
     */
    @Test
    public  void testgetAllDepts() throws Exception{
        //通过session的getMapper(传入接口类型的字节码)返回的是一个接口类型的对象
        IDeptDao mapper = session.getMapper(IDeptDao.class);
        //通过接口类型的对象中自己定制的方法，可以得到想要的结果
            List<Dept> list = mapper.getAllDepts();
            for (Dept dept : list) {
                System.out.println(dept.getDeptname());
            }
        
        
        
    }