Mybatis 单表操作

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1.新建Java Web或Java工程

2.导入相应的jar包（oracle驱动jar及Mybatis所需jar）

3.创建类，测试类，映射文件，配置文件

4.总体结构如下图

其中类为：

package me.gacl.domain;public class User {//实体类的属性和表的字段名称一一对应     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;     }      @Override    public String toString() {        return "User [id=" + id + ", name=" + name + ", age=" + age + "]";     }}

测试类为

package me.gacl.test;import java.io.IOException;import java.io.Reader;import java.util.List;import me.gacl.domain.User;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;public class Test {public static void main(String[] args) throws IOException { //mybatis的配置文件        //String resource = "conf.xml";        //使用类加载器加载mybatis的配置文件（它也加载关联的映射文件）        //InputStream is = Test.class.getClassLoader().getResourceAsStream(resource);        Reader reader = Resources.getResourceAsReader("conf.xml");        //构建sqlSession的工厂        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);        //使用MyBatis提供的Resources类加载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，         * me.gacl.mapping.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，         * getUser是select标签的id属性值，通过select标签的id属性值就可以找到要执行的SQL         */        String statement = "me.gacl.mapping.userMapper.getUser";//映射sql的标识字符串        //执行查询返回一个唯一user对象的sql        User wser1 = new User();        wser1.setId(2);        wser1.setName("孤傲苍狼");        User user = (User)session.selectOne(statement, wser1);//      List<User> list = (List)session.selectList(statement);//      for(User user:list){//      System.out.println(user); //      }        //        int user = (Integer)session.selectOne(statement);        System.out.println(user); }}

映射文件为

<?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="me.gacl.mapping.userMapper"> <select id="getUser" parameterType="me.gacl.domain.User"         resultType="me.gacl.domain.User">        select * from users where id=#{id} and name=#{name}    </select>    <select id="getUserList"         resultType="me.gacl.domain.User">        select * from users     </select></mapper>

配置文件为

<?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>     <environments default="development">         <environment id="development">             <transactionManager type="JDBC" />             <!-- 配置数据库连接信息 -->             <dataSource type="POOLED">                 <property name="driver" value="oracle.jdbc.driver.OracleDriver" />                <property name="url" value="jdbc:oracle:thin:@192.168.0.212:1521:orcl" />                <property name="username" value="newjw_zgzf141024" />                <property name="password" value="newjw_zgzf141024" />             </dataSource>         </environment>     </environments>      <mappers>            <mapper resource="me/gacl/mapping/userMapper.xml"/>      </mappers> </configuration>

准备sql语句：

--创建序列

create sequence users_sequence
increment by 1
start with 1
maxvalue 999999999;

--建表

CREATE TABLE users(id number PRIMARY KEY , NAME VARCHAR2(20), age number);
INSERT INTO users(id,NAME, age) VALUES(users_sequence.nextval,'孤傲苍狼', 27);
INSERT INTO users(id,NAME, age) VALUES(users_sequence.nextval,'白虎神皇', 27);

如图所示结果即为成功

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