实现核心功能，包括数据库设计，java代码编写。

使用 @用户 评论方法，避免了多重循环嵌套方式。

微博、思否就是用这种评论方式。

效果图：

微博（评论时间倒叙，从下向上看）：

思否

数据库设计：

涉及到三张表：

评论表 ↓

CREATE TABLE `pm_comment` (  `id` varchar(30) NOT NULL,  `pid` varchar(30) DEFAULT NULL,  `pictureid` varchar(30) DEFAULT NULL,  `userid` varchar(32) DEFAULT NULL COMMENT '评论用户id',  `beicommentuserid` varchar(32) DEFAULT NULL COMMENT '被评论用户id，如果添加根节点评论，则为空',  `commenttime` datetime DEFAULT NULL,  `isrelease` int(11) DEFAULT '1',  `isdel` int(11) DEFAULT '0',  PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;

 

评论内容表 ↓

CREATE TABLE `pm_commentcontent` (  `id` varchar(32) NOT NULL DEFAULT '',  `commentid` varchar(30) NOT NULL,  `commentcontent` varchar(500) NOT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;

 

用户表 ↓

CREATE TABLE `pm_user` (  `id` varchar(30) NOT NULL,  `account` varchar(20) NOT NULL,  `password` varchar(40) NOT NULL,  `nickname` varchar(20) DEFAULT NULL,  `avatar` varchar(200) DEFAULT NULL,  `gender` varchar(10) NOT NULL,  `phonenumber` varchar(11) NOT NULL,  `email` varchar(50) NOT NULL,  `createtime` datetime NOT NULL,  `updatetime` datetime DEFAULT NULL,  `isdel` int(11) NOT NULL DEFAULT '0',  PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;

 

 

关联查询出评论记录：

SELECT	pc.id,	pc.pid,	pc.pictureid,	pc.userid,	pu.account AS username,	pc.beicommentuserid,	pus.account AS beicommentusername,	pc.commenttime,	pc.isrelease,	pc.isdel,	pcc.commentcontent AS commentcontentFROM	pm_comment AS pcINNER JOIN pm_commentcontent AS pcc ON pc.id = pcc.commentidINNER JOIN pm_user AS pu ON pc.userid = pu.idLEFT JOIN pm_user AS pus ON pc.beicommentuserid = pus.idWHERE	pc.pictureid = '176476335496474624'-- AND pc.pid = '0'ORDER BY	pc.commenttime DESC

查询结果 ↓