初识mybatis_01

配置文件内容主要是数据库的连接：postgres

<?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>
     <!-- 顾名思义类型的别名,即 Person 代指com.sunmap.model.Person-->
    <typeAliases>
        <typeAlias alias="Person" type="com.sunmap.model.Person" />
        <typeAlias alias="Article" type="com.sunmap.model.Article" />
    </typeAliases>
    
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="org.postgresql.Driver" />
                <property name="url"
                    value="jdbc:postgresql://192.168.5.11:5432/poidata" />
                <property name="username" value="postgres" />
                <property name="password" value="123456" />
            </dataSource>
        </environment>
    </environments>
    
    <!--  -->
    <mappers>
        <mapper resource="com/sunmap/model/Person.xml" />
    </mappers>

</configuration>

预定义接口：

package com.sunmap.dao;

import java.util.List;

import com.sunmap.model.Article;
import com.sunmap.model.Person;

/**
 * 
 * 定义的接口
 * */
public interface IPersonOperation {

    public Person selectPersonByID(int id);
    
    public List<Person> selectPersonByName(String name);
    
    public void addPerson(Person p);
    
    public List<Person> selectPerson();
    
    public void updatePerson(Person p);

    public void deletePersonById(Person p);
    
    public List<Article> getUserArticle(int id);
}

定义的实体类Person：

package com.sunmap.model;

public class Person {
    private int id;
    private String name;
    private int age;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

Person.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 的作用，指向接口，即mybatis是面向接口编程，<select></select> 的id有指向接口的方法名；
个人理解<select></select> 就是接口的实现
 -->
<mapper namespace="com.sunmap.dao.IPersonOperation">
    <!-- 定义返回类型为集合 -->
    <resultMap type="Person" id="resultListUser">
        <id column="id" property="id" />
        <result column="name" property="name" />
        <result column="age" property="age" />
    </resultMap>
    <!-- 关联查询 -->
    <resultMap type="Article" id="resultArticleList">
        <id column="id" property="id" />
        <result column="text" property="text" />
        <association property="person" resultMap="resultListUser" column=""
            javaType="Person">
        </association>
    </resultMap>
    <select id="getUserArticle" parameterType="int" resultMap="resultArticleList">
        select person.id,person.name,person.age,article.id from person,article
        where person.id=article.personid and person.id=#{id}
    </select>
    <!-- 通过id查找 -->
    <select id="selectPersonByID" parameterType="int" resultType="Person">
        select * from person where id = #{id}
    </select>
    <!-- 查询数据 -->
    <select id="selectPerson" resultType="Person">
        select * from person
    </select>
    <select id="selectPersonByName" parameterType="String" resultMap="resultListUser">
        select * from person where name like '%${_parameter}%';
    </select>
    <!--插入数据 -->
    <insert id="addPerson" parameterType="Person">
         <selectKey keyProperty="id" resultType="int" order="BEFORE">
            SELECT nextval('test_c_id_seq'::regclass) as id  
         </selectKey>
        
        insert into person (id,name,age) values(#{id,jdbcType=INTEGER},#{name},#{age})
        
    </insert>
    <!-- 更新 -->
    <update id="updatePerson" parameterType="Person">
        update person set name =#{name},age = #{age} where id = #{id}
    </update>
    <!-- 删除 -->
    <delete id="deletePersonById" parameterType="Person">
        delete from person
        where id = #{id}
    </delete>
    <!-- 关联查询 -->
</mapper>
<!-- <mapper namespace="com.sunmap.dao"> <select id="selectPersonByID" parameterType="int" 
    resultType="Person"> select * from person where id = #{id} </select> <insert 
    id="addPerson" parameterType="Person" useGeneratedKeys="true" keyProperty="id"> 
    insert into Person (id,name,age) values(#{id},#{name},#{age}) insert into 
    person (name,age) values(#{name},#{age}) </insert> </mapper> -->

测试代码：

package com.sunmap.dao;

import static org.junit.Assert.*;

import java.io.IOException;
import java.io.Reader;
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 org.junit.Test;

import com.sunmap.model.Article;
import com.sunmap.model.Person;

public class TestIPersonOperation {

    @Test
    public void test() {
//        fail("Not yet implemented");
        try {
            Reader reader = Resources.getResourceAsReader("config/Configuration.xml");
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);  

            SqlSession session = sqlSessionFactory.openSession();
            IPersonOperation iPersonOperation = session.getMapper(IPersonOperation.class);
            
            
//            List<Article> list = iPersonOperation.getUserArticle(1);
//            System.out.println(list.size());
            /**
             * 删除
             * */
//            Person pp = new Person();
//            pp.setId(2);
//            iPersonOperation.deletePersonById(pp);
            /**
             * 更新
             * */
//            Person pp = new Person();
//            pp.setId(1);
//            pp.setName("update");
//            pp.setAge(234);
//            iPersonOperation.updatePerson(pp);
            /**
             * 添加数据(主键id自动增长,这个的需要创建一个序列)
             * 
             * CREATE SEQUENCE test_c_id_seq
                  INCREMENT 1
                  MINVALUE 1
                  MAXVALUE 9223372036854775807
                  START 1
                  CACHE 1;
                ALTER TABLE test_c_id_seq
                  OWNER TO postgres;
                  
                  然后关联上
                  alter table test_c alter column id set default nextval('test_c_id_seq');
                  
                  这个块其实挺恶心的～
             * */
//            Person pp = new Person();
//            pp.setName("sadfa");
//            pp.setAge(24);
//            iPersonOperation.addPerson(pp);
//            
//            
//            //提交事物
            session.commit();
            //查询
//             List<Person> personList = iPersonOperation.selectPerson();
//             for(Person p:personList){
//                 System.out.println(p.getName()+" : "+p.getAge());
//             }
            
            /**
             * 通过id查询
             * */
//            Person person = iPersonOperation.selectPersonByID(1);
//             System.out.println(person.getName()+":"+person.getAge());
             /**
              * 模糊查询（返回List集合）
              * 
              * 
              * 这块有两个需要注意的地方
              * 
              * 1. '%${_parameter}%'  ,单引号和#改成$
              * 2. 获取参数时：${_parameter}
              * 
              * 即：不管你的参数是什么，都要改成"_parameter"；
              * */
//             List<Person> personList = iPersonOperation.selectPersonByName("sa");
//             for(Person p:personList){
//                 System.out.println(p.getName()+" : "+p.getAge());
//             }
             
             //关闭session
             session.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }
    
}