JavaScript asp Tutorials more about Recordsets

JavaScript asp Tutorials more about Recordsets_asp basics

Last Update:2017-01-18 Source: Internet

Author: User

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Below we'll attempt to access data from a database without knowing the column names. Clearly the best way to utilize data in your The database are to keep track of your schema. Schema is the layout of data in your database. The concept is beyond the scope of this web site, but it is worth mentioning. Most good resources on SQL would also be good the 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&lT;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 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 are 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. 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" 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") 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 some Thing 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 ("&l T;/table> ") RS.
Close ();
RS = null;
Connectobj.close ();
Connectobj = null;
 %> </BODY> </HTML>

Click here to run the script in a new window.

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

If you like the new VBArray constructor your should know that you have the following methods: dimensions () Item () LBound () ToArray () and UBound().

This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to info-contact@alibabacloud.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

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