二、数据库、dao层、pojo类配置
1、数据库配置
本项目的目标是搭建一个简易论坛，基本功能包含注册、登陆、发帖、评论，进阶功能包含收藏和订阅，因此数据库中应当包含如下这些表：
（1）user表（用户表）:
<1>userID(用户ID，INT型，设置为主键，不能为空，自动增长）
<2>password(密码，VARCHAR型，不能为空)
<3>username(用户名，VARCHAR型，不能为空)
（2）note表（帖子表）：
<1>noteID(帖子ID，INT型，设置为主键，不能为空，自动增长)
<2>noteTitle(帖子标题，VARCHAR型，不能为空)
<3>noteContent(帖子内容，VARCHAR型，不能为空)
<4>time(发帖时间，TIMESTAMP型，不能为空)
<5>userID(发帖用户ID，INT型，不能为空)
<6>FK_note_user(与user表的多对一外键，级联删除，禁止修改)
（3）comment表（评论表）：
<1>commentID(评论ID，INT型，设置为主键，不能为空，自动增长)
<2>content(评论内容，VARCHAR型，不能为空)
<3>time(评论时间，TIMESTAMP型，不能为空)
<4>userID(评论用户ID，INT型，不能为空)
<5>noteID(帖子ID，INT型，不能为空)
<6>replyID(所回复的评论ID，INT型）
<7>FK_comment_user(与user表的多对一外键，级联删除，禁止修改)
<8>FK_comment_note(与note表的多对一外键，级联删除，禁止修改)
（4）collection表（收藏表）：
<1>collectionID(收藏ID，INT型，设置为主键，不能为空，自动增长)
<2>userID(收藏用户ID，INT型，不能为空)
<3>noteID(收藏帖子ID，INT型，不能为空)
<4>FK_collection_user(与user表的多对一外键，级联删除，禁止修改)
<5>FK_collection_note(与note表的多对一外键，级联删除，禁止修改)
SQL语句：
-- MySQL Workbench Forward Engineering
SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL,ALLOW_INVALID_DATES';
-- -----------------------------------------------------
-- Schema mydb
-- -----------------------------------------------------
-- -----------------------------------------------------
-- Schema bbs
-- -----------------------------------------------------
-- -----------------------------------------------------
-- Schema bbs
-- -----------------------------------------------------
CREATE SCHEMA IF NOT EXISTS `bbs` DEFAULT CHARACTER SET utf8 ;
USE `bbs` ;
-- -----------------------------------------------------
-- Table `bbs`.`user`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `bbs`.`user` (
`userID` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`password` VARCHAR(10) NOT NULL,
`username` VARCHAR(50) NOT NULL,
PRIMARY KEY (`userID`))
ENGINE = InnoDB
AUTO_INCREMENT = 21
DEFAULT CHARACTER SET = utf8;
-- -----------------------------------------------------
-- Table `bbs`.`note`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `bbs`.`note` (
`noteID` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`userID` INT(10) UNSIGNED NOT NULL,
`noteTitle` VARCHAR(45) NOT NULL,
`noteContent` VARCHAR(100) NOT NULL,
`time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`noteID`),
INDEX `FK_note_user` (`userID` ASC),
CONSTRAINT `FK_note_user`
FOREIGN KEY (`userID`)
REFERENCES `bbs`.`user` (`userID`)
ON DELETE CASCADE)
ENGINE = InnoDB
AUTO_INCREMENT = 9
DEFAULT CHARACTER SET = utf8;
-- -----------------------------------------------------
-- Table `bbs`.`collection`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `bbs`.`collection` (
`userID` INT(10) UNSIGNED NOT NULL,
`noteID` INT(10) UNSIGNED NOT NULL,
`collectionID` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`collectionID`),
INDEX `FK_collection_user_idx` (`userID` ASC),
INDEX `FK_collection_note_idx` (`noteID` ASC),
CONSTRAINT `FK_collection_note`
FOREIGN KEY (`noteID`)
REFERENCES `bbs`.`note` (`noteID`)
ON DELETE CASCADE,
CONSTRAINT `FK_collection_user`
FOREIGN KEY (`userID`)
REFERENCES `bbs`.`user` (`userID`)
ON DELETE CASCADE)
ENGINE = InnoDB
AUTO_INCREMENT = 31
DEFAULT CHARACTER SET = utf8;
-- -----------------------------------------------------
-- Table `bbs`.`comment`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `bbs`.`comment` (
`commentID` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`userID` INT(10) UNSIGNED NOT NULL,
`noteID` INT(10) UNSIGNED NOT NULL,
`content` VARCHAR(100) NOT NULL,
`time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`replyID` INT(10) NULL DEFAULT NULL,
PRIMARY KEY (`commentID`),
INDEX `FK_comment_user_idx` (`userID` ASC),
INDEX `FK_comment_note_idx` (`noteID` ASC),
CONSTRAINT `FK_comment_note`
FOREIGN KEY (`noteID`)
REFERENCES `bbs`.`note` (`noteID`)
ON DELETE CASCADE,
CONSTRAINT `FK_comment_user`
FOREIGN KEY (`userID`)
REFERENCES `bbs`.`user` (`userID`)
ON DELETE CASCADE)
ENGINE = InnoDB
AUTO_INCREMENT = 29
DEFAULT CHARACTER SET = utf8;
-- -----------------------------------------------------
-- Table `bbs`.`subscription`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `bbs`.`subscription` (
`userID` INT(10) UNSIGNED NOT NULL,
`subuserID` INT(10) UNSIGNED NOT NULL,
`subscriptionID` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`subscriptionID`),
INDEX `FK_subscription_user_idx` (`userID` ASC),
INDEX `FK_subscription_subuser_idx` (`subuserID` ASC),
CONSTRAINT `FK_subscription_subuser`
FOREIGN KEY (`subuserID`)
REFERENCES `bbs`.`user` (`userID`)
ON DELETE CASCADE,
CONSTRAINT `FK_subscription_user`
FOREIGN KEY (`userID`)
REFERENCES `bbs`.`user` (`userID`)
ON DELETE CASCADE)
ENGINE = InnoDB
AUTO_INCREMENT = 13
DEFAULT CHARACTER SET = utf8;
SET SQL_MODE=@OLD_SQL_MODE;
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;
2、dao层、pojo类配置
(1)在DB Browse中选择自己要使用的表，右键选择Hibernate Reverse Engineering
(2)按照下图所示进行配置后点击finish生成dao层、pojo类
(3)在applicationContext.xml中名为seesionfactory的bean中添加mappingResources属性，代码如下：
<property name="mappingResources">
<list>
<value>com/sxy/pojo/Comment.hbm.xml</value>
<value>com/sxy/pojo/Note.hbm.xml</value>
<value>com/sxy/pojo/User.hbm.xml</value>
<value>com/sxy/pojo/Collection.hbm.xml</value>
<value>com/sxy/pojo/Subscription.hbm.xml</value>
</list>
</property>
(4)在每个表的配置文件（.hbm.xml）中对多对一外键（many-to-one）的属性进行如下配置：
lazy="false" fetch="join"
激活外连接查询并关闭延迟加载
(5)已生成的dao层和pojo类以及.hbm.xml配置文件如下图所示：
