简单查询

1. 定义Users

　　　

package com.myapp.mybatis.model;  
  
public class Users {  
    private int id;  
    private String name;  
    private int age;  
    private String sex;  
  
    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;  
    }  
  
    public String getSex() {  
        return sex;  
    }  
  
    public void setSex(String sex) {  
        this.sex = sex;  
    }  
}  

 2. 定义UsersMapper

package com.myapp.mybatis.model;  
  
public interface UsersMapper {  
    public Users selectUsers(int id);  
  
    public void insertUsers(Users users);  
  
    public Users selectUser(int id);  
}  

3.定义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="com.myapp.mybatis.model.UsersMapper">  
    <resultMap type="Users" id="user">  <!--此结果集只将id,name,sex值对应到Users对象属性中-->
        <id property="id" column="id" javaType="int" jdbcType="INTEGER"/>  
        <result property="name" column="name" javaType="string" jdbcType="VARCHAR"/>  
        <result property="sex" column="sex" javaType="string" jdbcType="VARCHAR"/>  
    </resultMap>  
      
    <!-- 查询单一对象所有属性 -->  
    <select id="selectUsers" parameterType="int" resultType="Users">  <!--返回Users对象,对象所有的属性都将有对应值-->
        select id,name,age,sex from users where id = #{id}  
    </select>  
      
    <!-- 选择查询单一对象属性 -->  
    <select id="selectUser" parameterType="int" resultMap="user"> <!-- 对应resultMap type="Users" id="user"  的Map user 该Map为Users对象但只有id,name,sex属性有对应值--> 

　　select id,name,sex from users where id = #{id}  
    </select>  
      
    <!-- 主键自增插入mysql -->  
    <insert id="insertUsersMysql" parameterType="Users">  
        insert into users values(null,#{name},#{age},#{sex})  
    </insert>  
      
    <!-- 主键自增插入oracle -->  
    <insert id="insertUsers" parameterType="Users">  
        <selectKey keyProperty="id" resultType="int" order="BEFORE">  
            select seq_users.nextval from dual  
        </selectKey>  
        insert into users values(#{id},#{name},#{age},#{sex})  
    </insert>  
</mapper>  

4.定义configuration.xml

<?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>     
    <typeAliases>  
        <typeAlias alias="Users" type="com.myapp.mybatis.model.Users"/>  
    </typeAliases>  
      
    <environments default="development">  
        <environment id="development">  
            <transactionManager type="JDBC"/>  
            <dataSource type="POOLED">  
                <property name="driver" value="oracle.jdbc.driver.OracleDriver"/>  
                <property name="url" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/>  
                <property name="username" value="scott"/>  
                <property name="password" value="tiger"/>  
            </dataSource>  
        </environment>  
    </environments>  
      
    <mappers>  
        <mapper resource="com/nantian/mybatis/model/UsersMapper.xml"/>  
    </mappers>  
</configuration>  

4.定义DBUtil(用于读取SqlSession)

package com.myapp.mybatis.data;  
  
import java.io.IOException;  
import java.io.Reader;  
  
import org.apache.ibatis.io.Resources;  
import org.apache.ibatis.session.SqlSessionFactory;  
import org.apache.ibatis.session.SqlSessionFactoryBuilder;  
  
public class DBUtil {  
    private static final DBUtil dbUtil = new DBUtil();  
    private SqlSessionFactory sqlSessionFactory = null;  
  
    private DBUtil() {  
        try {  
            String resource = "com/nantian/mybatis/data/configuration.xml";  
            Reader reader = Resources.getResourceAsReader(resource);  
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);  
            reader.close();  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
    }  
  
    public static DBUtil getInstance() {  
        return dbUtil;  
    }  
  
    public SqlSessionFactory getSqlSessionFactory() {  
        return sqlSessionFactory;  
    }  
}  

5.Test 用于测试

package com.myapp.mybatis.test;  
  
import junit.framework.TestCase;  
  
import org.apache.ibatis.session.SqlSession;  
  
import com.myapp.mybatis.data.DBUtil;  
import com.myapp.mybatis.model.Users;  
import com.myapp.mybatis.model.UsersMapper;  
  
public class Test extends TestCase {  
    public void selectUser() {  
        SqlSession sqlSession = DBUtil.getInstance().getSqlSessionFactory()  
                .openSession();  
        try {  
            UsersMapper usersMapper = sqlSession.getMapper(UsersMapper.class);  
            Users user = usersMapper.selectUser(3);  
            System.out.println(user.getId());  
            System.out.println(user.getName());  
            System.out.println(user.getAge());  
            System.out.println(user.getSex());  
        } finally {  
            sqlSession.close();  
        }  
    }  
  
    public void selectUsers() {  
        SqlSession sqlSession = DBUtil.getInstance().getSqlSessionFactory()  
                .openSession();  
        try {  
            UsersMapper usersMapper = sqlSession.getMapper(UsersMapper.class);  
            Users users = usersMapper.selectUsers(1);  
            System.out.println(users.getId());  
            System.out.println(users.getName());  
            System.out.println(users.getAge());  
            System.out.println(users.getSex());  
        } finally {  
            sqlSession.close();  
        }  
    }  
  
    public void insertUsers() {  
        SqlSession sqlSession = DBUtil.getInstance().getSqlSessionFactory()  
                .openSession();  
        try {  
            UsersMapper usersMapper = sqlSession.getMapper(UsersMapper.class);  
            Users users = new Users();  
            users.setName("王五");  
            users.setAge(32);  
            users.setSex("神");  
            usersMapper.insertUsers(users);  
            sqlSession.commit();  
        } finally {  
            sqlSession.close();  
        }  
    }  
}  

转载：http://blog.csdn.net/zq9017197