Mybatis一对一关联查询（六）

二、创建MySQL数据库表

/*
SQLyog Ultimate v12.09 (64 bit)
MySQL - 5.7.18-log : Database - mybatis
*********************************************************************
*/


/*!40101 SET NAMES utf8 */;

/*!40101 SET SQL_MODE=''*/;

/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
CREATE DATABASE /*!32312 IF NOT EXISTS*/`mybatis` /*!40100 DEFAULT CHARACTER SET utf8 */;

USE `mybatis`;

/*Table structure for table `author` */

DROP TABLE IF EXISTS `author`;

CREATE TABLE `author` (
  `author_id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '作者ID主键',
  `author_username` varchar(30) NOT NULL COMMENT '作者用户名',
  `author_password` varchar(32) NOT NULL COMMENT '作者密码',
  `author_email` varchar(50) NOT NULL COMMENT '作者邮箱',
  `author_bio` varchar(1000) DEFAULT '这家伙很赖，什么也没留下' COMMENT '作者简介',
  `register_time` datetime DEFAULT CURRENT_TIMESTAMP COMMENT '注册时间',
  PRIMARY KEY (`author_id`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8;

/*Data for the table `author` */

insert  into `author`(`author_id`,`author_username`,`author_password`,`author_email`,`author_bio`,`register_time`) values (1,'张三','123456','123@qq.com','张三是个新手，刚开始注册','2015-10-29 10:23:59'),(2,'李四','123asf','lisi@163.com','魂牵梦萦 ','2015-10-29 10:24:29'),(3,'王五','dfsd342','ww@sina.com','康熙王朝','2015-10-29 10:25:23'),(4,'赵六','123098sdfa','zhaoliu@qq.com','花午骨','2015-10-29 10:26:09'),(5,'钱七','zxasqw','qianqi@qq.com','这家伙很赖，什么也没留下','2015-10-29 10:27:04'),(6,'张三丰','123456','zhangsf@qq.com','这家伙很赖，什么也没留下','2015-10-29 11:48:00'),(7,'张无忌','qwertyuiop','wuji@163.com','这家伙很赖，什么也没留下','2015-10-29 11:48:24');

/*Table structure for table `blog` */

DROP TABLE IF EXISTS `blog`;

CREATE TABLE `blog` (
  `blog_id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT 'BlogId主键',
  `blog_title` varchar(255) NOT NULL COMMENT 'blog标题',
  `author_id` int(11) unsigned NOT NULL COMMENT '作者ID外键',
  PRIMARY KEY (`blog_id`),
  KEY `fk_author_id` (`author_id`),
  CONSTRAINT `fk_author_id` FOREIGN KEY (`author_id`) REFERENCES `author` (`author_id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;

/*Data for the table `blog` */

insert  into `blog`(`blog_id`,`blog_title`,`author_id`) values (1,'小张的Blog',1),(2,'小李',2),(3,'王五不是人',3),(4,'赵地人',4),(5,'钱钱钱',5);

/*Table structure for table `posts` */

DROP TABLE IF EXISTS `posts`;

CREATE TABLE `posts` (
  `post_id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '文章主键ID',
  `post_subject` varchar(255) NOT NULL COMMENT '文章主题，标题',
  `post_body` text NOT NULL COMMENT '文章内容最大3000个字符',
  `blog_id` int(11) unsigned NOT NULL COMMENT 'Blog主键做外键',
  `createtime` datetime DEFAULT CURRENT_TIMESTAMP COMMENT '文章创建时间',
  PRIMARY KEY (`post_id`),
  KEY `fk_blog_id` (`blog_id`),
  CONSTRAINT `fk_blog_id` FOREIGN KEY (`blog_id`) REFERENCES `blog` (`blog_id`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8mb4;

/*Data for the table `posts` */

insert  into `posts`(`post_id`,`post_subject`,`post_body`,`blog_id`,`createtime`) values (1,'Mybatis入门一','什么是 MyBatis ？\r\nMyBatis 是支持定制化 SQL、存储过程以及高级映射的优秀的持久层框架。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。MyBatis 可以对配置和原生Map使用简单的 XML 或注解，将接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java对象)映射成数据库中的记录。',1,'2015-10-29 10:32:21'),(2,'Mybatis入门二','要使用 MyBatis， 只需将 mybatis-x.x.x.jar 文件置于 classpath 中即可。',1,'2015-10-29 10:32:52'),(3,'Oracle学习','Oracle Database，又名Oracle RDBMS，或简称Oracle。是甲骨文公司的一款关系数据库管理系统',2,'2015-10-29 10:33:26'),(4,'JAVA学习一','Java是由Sun Microsystems公司于1995年5月推出的Java面向对象程序设计语言和Java平台的总称',3,'2015-10-29 10:34:17'),(5,'PL/SQL','PL/SQL也是一种程序语言，叫做过程化SQL语言（Procedural Language/SQL）。PL/SQL是Oracle数据库对SQL语句的扩展',4,'2015-10-29 10:37:52'),(6,'CSS标签选择器','标签选择器\r\nID选择器\r\n类选择器\r\n特殊选择器',5,'2015-10-29 10:39:44'),(7,'javascript','js:是前端脚本语言',2,'2015-10-29 10:40:18');

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

二、创建项目添加jar包

三、创建实体类

Author.java

package com.cwp.entity;

import java.util.Date;

public class Author {
    //作者ID
    private int authorId;
    
    //作者用户名
    private String authorUserName;
    
    //作者密码
    private String authorPassword;
    
    //作者邮箱
    private String authorEmail;
    
    //作者介绍
    private int authorBio;
    
    //注册时间
    private Date registerTime;

    public int getAuthorId() {
        return authorId;
    }

    public void setAuthorId(int authorId) {
        this.authorId = authorId;
    }

    public String getAuthorUserName() {
        return authorUserName;
    }

    public void setAuthorUserName(String authorUserName) {
        this.authorUserName = authorUserName;
    }

    public String getAuthorPassword() {
        return authorPassword;
    }

    public void setAuthorPassword(String authorPassword) {
        this.authorPassword = authorPassword;
    }

    public String getAuthorEmail() {
        return authorEmail;
    }

    public void setAuthorEmail(String authorEmail) {
        this.authorEmail = authorEmail;
    }

    public int getAuthorBio() {
        return authorBio;
    }

    public void setAuthorBio(int authorBio) {
        this.authorBio = authorBio;
    }

    public Date getRegisterTime() {
        return registerTime;
    }

    public void setRegisterTime(Date registerTime) {
        this.registerTime = registerTime;
    }
    

}

Blog.java

package com.cwp.entity;

public class Blog {
    
    private int blogId;
    //blog标题
    private String blogTitle;
    //作者id
    private int authorId;
    public int getBlogId() {
        return blogId;
    }
    public void setBlogId(int blogId) {
        this.blogId = blogId;
    }
    public String getBlogTitle() {
        return blogTitle;
    }
    public void setBlogTitle(String blogTitle) {
        this.blogTitle = blogTitle;
    }
    public int getAuthorId() {
        return authorId;
    }
    public void setAuthorId(int authorId) {
        this.authorId = authorId;
    }
    
    

}

Posts.java

package com.cwp.entity;

import java.util.Date;

public class Posts {
    private int postId;
    //文章主题
    private String postSubject;
    //文章内容
    private String postBody;
    //bolg的id
    private int blogId;
    //文章创建时间
    private Date createTime;
    public int getPostId() {
        return postId;
    }
    public void setPostId(int postId) {
        this.postId = postId;
    }
    public String getPostSubject() {
        return postSubject;
    }
    public void setPostSubject(String postSubject) {
        this.postSubject = postSubject;
    }
    public String getPostBody() {
        return postBody;
    }
    public void setPostBody(String postBody) {
        this.postBody = postBody;
    }
    public int getBlogId() {
        return blogId;
    }
    public void setBlogId(int blogId) {
        this.blogId = blogId;
    }
    public Date getCreateTime() {
        return createTime;
    }
    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }
    
    

}

数据库配置文件db.properties

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=UTF-8
jdbc.username=root
jdbc.password=root

mybatis配置文件

<?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>
<properties resource="db.properties" />
<typeAliases>
<!--使用默认别名  -->
<package name="com.cwp.entity"/>
</typeAliases>
<environments default="development">
<environment id="development">
    <transactionManager type="JDBC"/>
    <dataSource type="POOLED">
        <property name="driver" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </dataSource>
</environment>
</environments>
<mappers>
<!-- 加载映射 -->

<package name="com.cwp.mapper"/>
</mappers>
</configuration>