maybatis(2)

package com.dao.Impl;

import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

import com.dao.UserDao;
import com.pojo.User;

public class UserDaoImpl implements UserDao {
    // 用它获取SQLSession对象(相当于connection)
    private SqlSessionFactory sqlSessionFactory;
    public UserDaoImpl(SqlSessionFactory sqlSessionFactory) {
        super();
        this.sqlSessionFactory = sqlSessionFactory;
    }
    
//插入,更新,删除都要提交事务    

    @Override
    public int saveUser(User user) {
        // TODO Auto-generated method stub
        SqlSession session=sqlSessionFactory.openSession();
        int result=-1;
        try {
            //第一个参数是名称空间.id
            result=session.insert("com.pojo.User.saveUser",user);
            session.commit();
        } finally {
            // TODO: handle finally clause
            session.close();
        }
        return result;
    }

    @Override
    public int deleteUserById(Integer id) {
        // TODO Auto-generated method stub
        SqlSession session=sqlSessionFactory.openSession();
        int result=-1;
        try {
            //第一个参数是名称空间.id
            result=session.delete("com.pojo.User.deleteUserById",id);
            session.commit();
        } finally {
            // TODO: handle finally clause
            session.close();
            
        }
        return result;
    }
    

    @Override
    public int update(User user) {
        // TODO Auto-generated method stub
        SqlSession session=sqlSessionFactory.openSession();
        int result=-1;
        try {
            //第一个参数是名称空间.id
            result=session.delete("com.pojo.User.updateUser",user);
            session.commit();
        } finally {
            // TODO: handle finally clause
            session.close();
        }
        return result;
    }

    @Override
    //
    public User queryUserById(Integer id) {
        // TODO Auto-generated method stub
        
        SqlSession session=sqlSessionFactory.openSession();
        
        try {
            //第一个参数是名称空间.id
            return session.selectOne("com.pojo.User.queryUserById",id);
        } finally {
            // TODO: handle finally clause
            session.close();
        }
        
    }

    @Override
    public List<User> queryUsers() {
        // TODO Auto-generated method stub
SqlSession session=sqlSessionFactory.openSession();
        
        try {
            //第一个参数是名称空间.id
            return session.selectList("com.pojo.User.queryUsers");
        } finally {
            // TODO: handle finally clause
            session.close();
        }
        
    }

}

<?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.pojo.User">

<!--     public int saveUser(User user);
        insert标签配置insert语句
            id属性配置唯一的标识
            parameterType 设置方法的参数类型（可以省略，一般如果是JavaBean，不推荐省略）
            useGeneratedKeys="true" 表示使用数据库生所的主键
            keyProperty="id" 属性设置将数据库中返回的自增id值交给哪个属性
 -->
    <insert id="saveUser" parameterType="com.pojo.User">
        <!-- 
            order属性设置selectKey里配置的sql语句的执行顺序
                AFTER        在insert语句之后执行
                BEFORE        在insert语句之前执行
                keyProperty="id" 属性设置将数据库中返回的自增id值交给哪个属性
                resultType="int" 属性表示查询之后返回的类型
                int    表示Integer类型
         -->
        <selectKey order="AFTER" keyProperty="id" resultType="int">
            select last_insert_id()
        </selectKey>
        insert into t_user(`last_name`,`sex`) values(#{lastName},#{sex})
    </insert>
<!--     public int deleteUserById(Integer id); -->
    <delete id="deleteUserById">
        delete from t_user where id = #{id}
    </delete>
<!--     public int updateUser(User user); -->
    <update id="update" parameterType="com.pojo.User">
        update t_user set last_name=#{lastName},sex=#{sex} where id = #{id}
    </update>
<!--     
        select 标签配置select查询语句
            id 属性给当前的sql语句配置一个唯一标识
            resultType 属性设置查询结果每行记录对应生成的JavaBean的全类名
            parameterType 设置方法的参数类型（可以省略）
 -->
    <select id="queryUserById" parameterType="int" resultType="com.pojo.User">
        select id,last_name lastName,sex from t_user where id = #{id}
    </select>
<!--     public List<User> queryUsers(); -->
    <select id="queryUsers" resultType="com.pojo.User">
        select id,last_name lastName,sex from t_user
    </select>

</mapper>