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  • Mybatis框架 的快速入门

    MyBatis

     简介

    什么是 MyBatis?

    MyBatis 是支持普通 SQL 查询,存储过程和高级映射的优秀持久层框架。MyBatis 消除 了几乎所有的 JDBC 代码和参数的手工设置以及结果集的检索。MyBatis 使用简单的 XML 或注解用于配置和原始映射,将接口和 Java 的 POJOs(Plan Old Java Objects,普通的 Java 对象)映射成数据库中的记录。

    Mybatis快速入门

    1.添加jar包

    mybatis:

      mybatis-3.1.1.jar

    oracle:

     ojdbc6.jar(根据个人情况,不同数据库选择相应的包)

    2.表

     create table user_name (id number,name varchar2(200),age number);
    
    insert into user_name values(1,'ddd',23);
    
    insert into user_name values(2.'fff',24)
    View Code

    3.添加mybatis的配置文件config.xm

     1 <?xml version="1.0" encoding="UTF-8"?>
     2 
     3 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
     4 
     5 <configuration>
     6 
     7          <environments default="development">
     8 
     9                    <environment id="development">
    10 
    11                             <transactionManager type="JDBC" />
    12 
    13                             <dataSource type="POOLED">
    14 
    15                                      <property name="driver" value="oracle.jdbc.driver.OracleDriver" />
    16 
    17                                      <property name="url" value="jdbc:oracle:thin:@localhost:1521:Oracle" />
    18 
    19                                      <property name="username" value="root" />
    20 
    21                                      <property name="password" value="root" />
    22 
    23                             </dataSource>
    24 
    25                    </environment>
    26 
    27          </environments>
    28 
    29 </configuration>
    View Code

    4.定义表所对应的实体类

    package cn.zr.maybatis;
    
    public class User {
     
        private String id;
        
        private String userName;
        
        private String passWord;
    
        public User() {
            super();
            // TODO Auto-generated constructor stub
        }
    
        public User(String id, String userName, String passWord) {
            super();
            this.id = id;
            this.userName = userName;
            this.passWord = passWord;
        }
    
        public String getId() {
            return id;
        }
    
        public void setId(String id) {
            this.id = id;
        }
    
        public String getUserName() {
            return userName;
        }
    
        public void setUserName(String userName) {
            this.userName = userName;
        }
    
        public String getPassWord() {
            return passWord;
        }
    
        public void setPassWord(String passWord) {
            this.passWord = passWord;
        }
    
        @Override
        public String toString() {
            return "User [id=" + id + ", userName=" + userName + ", passWord=" + passWord + "]";
        }
        
        
        
    }
    View Code

    5.定义操作user_name表的sql映射文件userMapper.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"> 
    <mapper namespace="cn.zr.mybatis.userMapper"> 
    <select id="getUser" parameterType="int" 
    resultType="cn.zr.mybatis.User">
    select * from user_name where id=#{id}
    </select>
    </mapper>

    6.在config.xml文件中注册userMapper.xml文件

    <mappers>
    <mapper resource="cn/zr/mybatis/userMapper.xml"/>
    </mappers>

    7.编写测试代码,执行定义的select语句

    public class Test {
    
             public static void main(String[] args) throws IOException {
    
                       String resource = "config.xml";
    
                       //加载mybatis的配置文件(它也加载关联的映射文件)
    
                       Reader reader = Resources.getResourceAsReader(resource);
    
                       //构建sqlSession的工厂
    
                       SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);
    
                       //创建能执行映射文件中sql的sqlSession
    
                       SqlSession session = sessionFactory.openSession();
    
                       //映射sql的标识字符串
    
                       String statement = "com.atguigu.mybatis.bean.userMapper"+".selectUser";
    
                       //执行查询返回一个唯一user对象的sql
    
                       User user = session.selectOne(statement, 1);
    
                       System.out.println(user);
    
                      session.commit();
    
                      session.close();
    
             }
    
    }
    View Code
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  • 原文地址:https://www.cnblogs.com/yxh1008/p/5990464.html
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