当前位置: 首页 > 图文教程 > 网络编程 > ASP > javascript asp教程More About Recordsets

ASP
批量文件自动搜索替换插入器 Ver2.1
用asp实现批量删除bak文件
在线扫描探测检查asp站点木马后门的程序
[原创]随机增加网站点击的一个不错的方法
flash和asp分页的一点心得与flash脚本
ASP中常用的函数和详细说明
用javascript编写asp应用--第一课--通览
javascript asp教程第四课 同时使用vbscript和javascript
javascript asp教程第五课--合二为一
javascript asp教程第七课--response属性
javascript asp教程第八课--request对象
javascript asp教程第九课--cookies
javascript asp教程第十课--global asa
javascript asp教程第十一课--Application 对象
javascript asp教程第十二课---session对象
javascript asp教程第十三课－－include文件
javascript asp教程服务器对象
javascript asp教程错误处理
javascript asp教程创建数据库连接
javascript asp教程Recordset记录

No. « 53 54 55 56 »

技术文章搜索

关键字

ASP 中的 javascript asp教程More About Recordsets

出处:互联网   整理: 软晨网（RuanChen.com）   发布: 2009-09-13   浏览: 32 ::
收藏到网摘: n/a

Below we will attempt to access data from a database without knowing the column names. Clearly the best way to utilize data in your database is to keep track of your schema. Schema is the layout of data in your database. The concept is well beyond the scope of this web site, but it is worth mentioning. Most good resources on SQL will also be good resources on database management. Better database schema leads to better ASP code.

Get Started:

Below is the script for Lesson 18. 

<%@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("\\")
myConnect += "\\GlobalScripts\\htmlColor.mdb;";
var ConnectObj = Server.CreateObject("ADODB.Connection");
var RS = Server.CreateObject("ADODB.Recordset");
var sql="SELECT * FROM colorChart;";
ConnectObj.Open (myConnect);
RS.Open(sql,ConnectObj,adOpenForwardOnly,adLockReadOnly,adCmdText);
var recordCount = RS.Fields.Count;
var x = 0;
var getFieldNames = false;
Response.Write("<TABLE BORDER=\"1\" CELLSPACING=\"0\">\r");
while (!RS.EOF)	{	if (x >= recordCount)	{	x = 0	}	Response.Write("<TR>");	if (!getFieldNames)	{	while (x <= recordCount-1)	{	Response.Write("<TH>" + RS.Fields(x).Name + "</TH>");	x++;	}	getFieldNames = true;	x = 0;	Response.Write("</TR>\r<TR>")	}	while (x <= recordCount-1)	{	Response.Write("<TD>" + RS.Fields(x).Value + "</TD>");	x++;	}	Response.Write("</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.

I don't think this needs much explaining. The RS.Fields.Count tells us how many columns wide the Recordset is. For each row, we loop through columns using either RS.Fields(x).Name for the colum name or RS.Fields(x).Value for the datum in said column.

Another Way:

A potentially more elegant way to accomplish this same goal is to use the ADO Method GetRows. It returns a multi-dimensional array containing the Recordset data. WAIT! Aren't JavaScript Arrays lexical (and flat)? Yes. We can emulate multi-dimensional arrays, but in reality they are flat. So it's a no-go on the GetRows... unless we do something really creative. 

<%@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("\\")
myConnect += "\\GlobalScripts\\htmlColor.mdb;";
var ConnectObj = Server.CreateObject("ADODB.Connection");
var RS = Server.CreateObject("ADODB.Recordset");
var sql="SELECT * FROM colorChart;";
ConnectObj.Open (myConnect);
RS.Open(sql,ConnectObj,adOpenForwardOnly,adLockReadOnly,adCmdText);
var myArray = RS.GetRows().toArray();
Response.Write("Let's see the results of myArray as JavaScript");
Response.Write(" sees them (which is flat).<BR>\r");
Response.Write(myArray + "<BR><BR>\r")
RS.MoveFirst();
var myVBArray = new VBArray(RS.GetRows())
Response.Write("We can use the <I>new VBArray</I> constructor and the ")
Response.Write("<I>getItem( )</I> method. For example: myVBArray.getItem(1,1) ")
Response.Write("returns " + myVBArray.getItem(1,1) + "<BR><BR>\r")
Response.Write("Now lets make something useful.<BR>\r")
Response.Write("<TABLE BORDER=1 CELLPADDING=0 CELLSPACING=0>")
Response.Write("\r<TR>")
for (var x=0; x<=myArray.length-1; x++)	{	Response.Write("<TD>" + myArray[x] + "</TD>")	if ((x+1)%RS.Fields.Count==0)	{	Response.Write("</TR>\r<TR>")	}	}
Response.Write("</TR>\r")
Response.Write("</TABLE>")
RS.Close();
RS = null;
ConnectObj.Close();
ConnectObj = null;
%>
</BODY>
</HTML>

Click Here to run the script in a new window.

Notice when we use getRows( ) we don't get the column names (but that would be really easy to fix). The problem with myArray is that it's not very useful in its raw state. So we use a modulo operator and thanks to a little thing called RS.Fields.Count we can tell how many times we write data to the table before staring a new table row.

If you like the new VBArray constructor you should know that you have the following methods: dimensions() getItem() lbound() toArray() and ubound().