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

ASP
JS复制特定内容到粘贴板
ASP+Access数据库安全设置方法小结
ADSI+ASP添加IP到IIS禁止访问列表中
ASP Google的translate API代码
最小asp后门程序
asp xml 缓存类
asp 过滤尖括号内所有内容的正则代码
ASP去掉字符串头尾连续回车和空格的Function
ASP IE地址栏参数的判断
SQL 注入式攻击的终极防范
ASP也使用ORM,给ASP上所有的SQL注入画上句号
判断Session的过期时间 采用JavaScript实时显示剩余多少秒
asp 动态生成rss(不成生xml文件)代码
ASP XML制作菜单管理程序
asp之自动闭合HTML/ubb标签函数附简单注释
asp 读取文件和保存文件函数代码
asp 随机字符串函数
asp form 表单验证函数
ASP 循环导入导出数据处理 不使用缓存
asp 数据库连接函数代码

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: 160 ::
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().