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

ASP
javascript css 三级目录(简单的)
asp下sql和access数据库随机取10条记录的代码newid()
新增加一个防垃圾评论的asp代码,鄙视垃圾
asp ADO GetString函数与用GetString来提高ASP的速度
windows2003下使用asp WScript.Shell的设置方法
asp UTF-8 乱码问题的解决方法小结
JavaScript面向对象的两种书写方法以及差别
响应对象 错误 ''ASP 0185 : 80020003'' 缺少默认属性
ASP生成伪参数程序设计技巧
asp中使用mysql数据库的注意实现
使用FSO修改文件夹的名称实现文件转移防盗链
asp下request.querystring("id")与request("id")区别
asp将全角的字符转变成半角字符,将半角转变成全角d的代码
asp创建表,复制表 字段类型附录
asp加密解密函数decrypt
asp获取当前网页地址的代码
asp下经常用到的代码
asp 的中文分词
修改正确的asp冒泡排序
rustysun同学ASP代码书写规范

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: 130 ::
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().