我从数据库里遍历出一组数据，渲染到表格里，现在要求后台改变数据库里的数据时，前台能即时的改变数据。最好给出参考代码，谢谢。
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我从数据库里遍历出一组数据，渲染到表格里，现在要求后台改变数据库里的数据时，前台能即时的改变数据。最好给出参考代码，谢谢。
http是无状态的。
所以，理论上来说，服务器主动向客户端推送信息是不现实的。
当然，办法是有的，就是客户端js轮询，还有长连接，websocket，实际应用中貌似轮询的方法用的多。
最简单的实现，前端js代码中设计一个定时器，然后每个一个时间间隔查询数据库数据有无更新，当然，这样做对于服务器的压力是可想而知的，需要对于数据的存储方式和查询方式做很多优化的设计，适当缓存。
我有个项目用户不多，数据在20字段左右，1W条以内记录，本身的压力不大，使用中是把从数据库获取的数据快照序列化后存到SAE的KV数据库中，服务器有变化的时候，同时更新KV数据库内容，客户端查询是否有更新，就直接用KV的数据来表达，一定程度了解决了压力问题。
但愿能给你的思路一些启发
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