xmlHTTP technology:
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1. Database remote management technology
An important part of modern Internet-based applications of WAN is remote monitoring of databases. First, let’s briefly review the development process and methods of database remote management technology on the Internet:
In the early days, the database was remotely managed by writing CGI-BIN program module. However, CGI-BIN is slow to run and is inconvenient to maintain, and is now basically deprecated.
In recent years, there have been many applications using component object models (ComponentObjectModel, COM) and the effect is also very good. However, if you are using a third-party server (the author's website is built on a third-party virtual host), the server often does not allow users to register their own components due to confidentiality or other commercial reasons.
In recent years, the .NET platform launched by Microsoft and the J2EE platform of SUN are both very high-end database remote management and service platforms. All can provide high-quality multi-layer (n-Tier) application services.
Among them, .NET's Simple Object Access Protocol (SOAP) uses HypertextTransferProtocol (HTTP) and Extensible Markup Language (XML) technology to implement cross-system (such as Windows-Linux) communication service methods have been widely accepted and used by developers. Many large-scale applications, such as enterprise resource planning (ERP), are built on such large-scale platforms.
However, for small and medium-sized applications, such as the construction and maintenance of a website, such large-scale application platforms seem to be a bit too large and the overhead is too huge.
Microsoft, which once lagged behind in Internet technology and Java technology, is ahead of the development of XML application. The XMLHTTP protocol in her XML parser (MSXML) is a very convenient and practical customer/service communication pipeline. Comprehensive use of XMLHTTP and ActiveX data objects (ActiveXDataObjects, ADO/ADOX) can easily and conveniently implement remote database management.
This article introduces how to use XMLHTTP and ADO/ADOX in a comprehensive way for remote database management.
2. Database remote management system
The task process for remote database management is:
1. The client issues query or modify instructions for database structure and data to the server.
2. The server accepts and executes relevant instructions and returns the results to the client.
3. The client accepts and displays the execution results of the instruction returned by the server.
The two main key links in realizing remote database management are:
1. The data channel for uploading instructions and downloading results between the client and the server is implemented by the XMLHTTP protocol.
2. The instruction transmission and result return between the server front-end and the database are completed by the ADO/ADOX interface that plays the role of the intermediate layer.
3. Use of XMLHTTP
As the name suggests, XMLHTTP is a hypertext transmission protocol that transmits XML format data.
In fact, the data transmission process of XMLHTTP is more flexible:
The instructions it uploads can be XML format data, a string, a stream, or an array of unsigned integers. It can also be a URL parameter.