文章出处:  http://www.informit.com/articles/article.aspx?p=24094 In the preceding two chapters, I discussed dbExpress—a unidirectional database technology. In the real world, most applications support bidirectional scrolling through a dataset. As noted p…

TField.CurValue Property Represents the current value of the field component including changes made by other users of the database Description Use CurValue to examine the value of a field when a problem occurs while posting a value to the database us…

1. WebSockets -- full-duplex communication The main HTML5 pillars include Markup, CSS3, and JavaScript APIs For whole set of HTML5, visit html5rocks.com (google product)   The URL The following image shows the WebSocket URL example in tokens: schema…

FireDac 的一些应用提示: 1. 客户端 dataset 能用 TFDQuery 连接  dataset provider 获取数据 ? Can I use TFDQuery and connect it to a dataset provider and retrieve the data in an Embarcadero client dataset? 参考 http://docwiki.embarcadero.com/RADStudio/Tokyo/en/TFDQuery,_TFD…

http://www.cnblogs.com/Kim53622744/p/4428997.html 在cxgrid中增加选择列 1.在dataset(query/table/clientdataset etc.)fieldeditor中增加计算字段fdSelect,datatype 为string,当然也可以其它类型.fieldkind设为fkCalculated或fkInternalCalc:设为fkInternalCalc时,应当注意在选择语句如下写:select '0' as fdsele…

很久没有去动Delphi了,突然兴起做个小程序,一个表的ID,在服务器端的应用服务器上生成,如何刷新到客户端? 查看了TDataSetProvider的Options属性,比以前增加了一个poPropogateChanges,解释如下: Changes made by the server to updated records as part of the update process are sent back to the client and merged into the client…

看到一篇介绍ClientDataSet和TDataSetProvider,非常精彩,特此保存. =========================================================================== TClientDataSet用法 第十一章 TClientDataSet 与TTable.TQuery一样,TClientDataSet也是从TDataSet继承下来的,它通常用于多层体系结构的客户端.TClientDataSet最大的特点是它不依赖于…

1. SrsRtmpConn::service_cycle 当服务器在 conn 线程的开始调用 connect_app 函数接收并解析客户端发送的 connect 消息后,调用该 service_cycle 函数开始服务客户端的具体请求. /** * when valid and connected to vhost/app, service the client. */ int SrsRtmpConn::service_cycle() { int ret = ERROR_SUCCESS; /…

Getting-started-with-sql-and-bigquery 教程 结构化查询语言(SQL)是数据库使用的编程语言,它是任何数据科学家的一项重要技能. 在本课程中,您将使用BigQuery来提高SQL技能,BigQuery是一种Web服务,可用于将SQL应用于庞大的数据集.在本课程中,您将学习访问和检查BigQuery数据集的基础知识. 在您掌握了这些基础知识之后,我们将再次建立您的SQL技能. Your first BigQuery commands 要使用BigQuery,我们…

NEST 索引DataSet数据,先序列化然后转成dynamic 类型进行索引: /// <summary> /// 索引dataset /// </summary> /// <param name="dataSet"></param> /// <param name="taskId"></param> public void Insert(DataSet dataSet,int taskId)…