Execute, Requery, and Clear Methods Example (JScript)

Artikkeli
11/18/2022

This example demonstrates the Execute method when run from both a Command object and a Connection object. It also uses the Requery method to retrieve current data in a Recordset, and the Clear method to clear the contents of the Errors collection. (The Errors collection is accessed via the Connection object of the ActiveConnection property of the Recordset.) Name the file ExecuteJS.asp.

<!-- BeginExecuteJS -->  
<%@LANGUAGE="JScript"%>  
<%// use this meta tag instead of adojavas.inc%>  
<!--METADATA TYPE="typelib" uuid="00000205-0000-0010-8000-00AA006D2EA4" -->  
  
<%  
    strLastName = new String(Request.Form("AuthorLName"));  
  
    if (strLastName.indexOf("undefined") > -1)  
        strLastName = "";  
%>  
  
<html>  
  
<head>  
<title>Execute, Requery and Clear Methods Example (JScript)</title>  
<style>  
<!--  
BODY {  
   font-family: 'Verdana','Arial','Helvetica',sans-serif;  
   BACKGROUND-COLOR:white;  
   COLOR:black;  
    }  
-->  
</style>  
</head>  
  
<body bgcolor="White">  
<h1>Execute, Requery and Clear Methods Example (JScript)</h1>  
<%  
    if (strLastName.length > 0)  
    {  
        // command and recordset variables  
        var Connect = "Provider='sqloledb';Data Source=" + Request.ServerVariables("SERVER_NAME") + ";" +  
            "Initial Catalog='pubs';Integrated Security='SSPI';";  
        var Cnxn = Server.CreateObject("ADODB.Connection");  
        var cmdAuthor = Server.CreateObject("ADODB.Command");  
        var rsAuthor = Server.CreateObject("ADODB.Recordset");  
        var rsAuthor2 = Server.CreateObject("ADODB.Recordset");  
        var SQLAuthor2, strMessage, strMessage2;  
        var Err, ErrCount;  
  
        try  
        {  
            // open connection  
            Cnxn.Open(Connect);  
  
            // command object parameters  
            cmdAuthor.CommandText = "SELECT * FROM Authors WHERE au_lname = ?";  
            cmdAuthor.Parameters.Append(cmdAuthor.CreateParameter("Last Name", adChar, adParamInput, 20, strLastName));  
            cmdAuthor.ActiveConnection = Cnxn;  
  
            // recordset from command.execute  
            rsAuthor = cmdAuthor.Execute();  
  
            // recordset from connection.execute  
            SQLAuthor2 = "SELECT * FROM Authors";  
            rsAuthor2 = Cnxn.Execute(SQLAuthor2);  
  
                // check for errors  
                ErrCount = Cnxn.errors.count;  
                if(ErrCount !== 0) //write the errors  
                {  
                    for(Err = 0; Err = ErrCount; Err++){  
                        Err = Cnxn.errors.item;  
                        Response.Write(Err);  
                    }  
                    // clean out any existing errors  
                    Cnxn.Errors.Clear;  
                }  
  
                // show the data      
            Response.Write("<HR><HR>");  
  
                // first recordset  
            Response.Write("<b>Command.Execute results</b>")  
            while (!rsAuthor.EOF)  
            {  
                // build output string by starting a new line  
                strMessage = "<P>";  
                strMessage += "<br>";  
  
                // recordset data   
                strMessage += rsAuthor("au_fname") + " ";   
                strMessage += rsAuthor("au_lname") + " ";  
  
                // end the line  
                strMessage += "</P>";  
  
                // show the results  
                Response.Write(strMessage);  
  
                // get next record  
                rsAuthor.MoveNext;  
            }  
  
            Response.Write("<HR><HR>");  
  
            // second recordset  
            Response.Write("<b>Connection.Execute results</b>")  
            while (!rsAuthor2.EOF)  
            {  
                // start a new line  
                strMessage2 = "<P>";  
  
                // first and last name are in first column  
                strMessage2 += rsAuthor2("au_fname") + " "   
                strMessage2 += rsAuthor2("au_lname") + " ";  
  
                // end the line  
                strMessage2 += "</P>";  
  
                // show results  
                Response.Write(strMessage2);  
  
                // get next record  
                rsAuthor2.MoveNext;  
            }  
        }  
        catch (e)  
        {  
            Response.Write(e.message);  
        }  
        finally  
        {  
            // clean up  
            if (rsAuthor.State == adStateOpen)  
                rsAuthor.Close;  
            if (rsAuthor2.State == adStateOpen)  
                rsAuthor2.Close;  
            if (Cnxn.State == adStateOpen)  
                Cnxn.Close;  
            rsAuthor1 = null;  
            rsAuthor2 = null;  
            Cnxn = null;  
        }  
    }  
%>  
  
<hr>  
  
<form method="POST" action="ExecuteJS.asp" id=form1 name=form1>  
  <p align="left">Enter last name of author to find (e.g., Ringer): <input type="text" name="AuthorLName" size="40"></p>  
  <p align="left"><input type="submit" value="Submit" name="B1"><input type="reset" value="Reset" name="B2"></p>  
</form>  
</body>  
  
</html>  
<!-- EndExecuteJS -->

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Execute, Requery, and Clear Methods Example (JScript)

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