While this section is devoted to ASP database utilization, it very important to remember that this web site is not intended to be a thorough ASP resource. Remember, the focus of this site is strictly limited to how to use JavaScript as your primary scripting language for ASP.
You'll see how to construct connection strings in JavaScript, use JavaScript loops to manipulate recordsets, convert the JavaScript Date Object into a format that databases can accept, and to some extent you'll see how to make SQL statements in JavaScript.
You can find a lot of good resources on database utilization. Those resources, coupled with the next four lessons, will be everything you need to write ASP JavaScript database applications.
The Connection Object:
The connection object is the link between the database and your ASP script. Remember, it's a created or instanciated object, so we can have two or more instances of Connection on one page. Connection has eight (8) methods, eleven (11) properties, nine (9) events, and finally it has two (2) properties. We will discuss three of the methods, one of the properties, and then we will forego the rest.
There are four common connections. 1) MDL 2) DSN 3) ODBC 4) OLE-DB. MDL stands for Microsoft Data Link. Don't use it. Also, please don't use a DSN; it's slow and outdated and nobody recommends it. ODBC is better, but it's not the best. The recommended connection type is OLE-DB. That's the type of connection you'll see demonstrated below.
Get Started:
Below is the script for Lesson 16. Don't try to understand it yet. We will slowly pick this thing apart down below.
<%@LANGUAGE="JavaScript"%><!-- METADATA TYPE="typelib" FILE="C:/Program Files/Common Files/System/ado/msado15.dll" --><HTML><BODY><%var myConnect = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source="; myConnect += Server.MapPath("http://");myConnect += "http://GlobalScripts//htmlColor.mdb;";var ConnectObj = Server.CreateObject("ADODB.Connection");var RS = Server.CreateObject("ADODB.Recordset");var sql="SELECT ID, colorName, hexValue FROM colorChart;";ConnectObj.Open (myConnect);RS.Open(sql,ConnectObj,adOpenForwardOnly,adLockReadOnly,adCmdText);Response.Write("<TABLE BORDER=/"1/" CELLSPACING=/"0/">/r");Response.Write("<TR><TH>ID</TH><TH>colorName</TH>");Response.Write("<TH>hexValue</TH></TR>/r");while (!RS.EOF) { Response.Write("<TR><TD>" +RS("ID")+ "</TD><TD BGCOLOR=/"#"); Response.Write( RS("hexValue")+ "/">" + RS("colorName") ); Response.Write("</TD><TD>" +RS("hexValue")+ "</TD></TR>/r"); RS.MoveNext(); }Response.Write("</TABLE>/r");RS.Close();ConnectObj.Close();RS = null;ConnectObj = null;%></BODY></HTML>Click Here to run the script in a new window.
Connection String:
This is by no means the most sophisticated database application ever built, but it will demonstrate everything we need to do. Let's start by looking at the connection string reprinted below.
新聞熱點
疑難解答
