• 初识mybatis_01


    配置文件内容主要是数据库的连接:postgres
     1 <?xml version="1.0" encoding="UTF-8" ?>
     2 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
     3 "http://mybatis.org/dtd/mybatis-3-config.dtd">
     4 <configuration>
     5      <!-- 顾名思义类型的别名,即 Person 代指com.sunmap.model.Person-->
     6     <typeAliases>
     7         <typeAlias alias="Person" type="com.sunmap.model.Person" />
     8         <typeAlias alias="Article" type="com.sunmap.model.Article" />
     9     </typeAliases>
    10     
    11     <environments default="development">
    12         <environment id="development">
    13             <transactionManager type="JDBC" />
    14             <dataSource type="POOLED">
    15                 <property name="driver" value="org.postgresql.Driver" />
    16                 <property name="url"
    17                     value="jdbc:postgresql://192.168.5.11:5432/poidata" />
    18                 <property name="username" value="postgres" />
    19                 <property name="password" value="123456" />
    20             </dataSource>
    21         </environment>
    22     </environments>
    23     
    24     <!--  -->
    25     <mappers>
    26         <mapper resource="com/sunmap/model/Person.xml" />
    27     </mappers>
    28 
    29 </configuration>
    View Code
    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);
    }
    View Code
    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;
        }
    }
    View Code
    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> -->
    View Code
    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();
            }
            
        }
        
    }
    View Code

     

    想的都是好
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  • 原文地址:https://www.cnblogs.com/freezone/p/5139755.html
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