Q246069: Encoding Form Data for SQL Server Input and Output to HTML
Article: Q246069
Product(s): Internet Information Server
Version(s): 5.0
Operating System(s):
Keyword(s):
Last Modified: 13-MAY-2002
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The information in this article applies to:
- Microsoft Internet Information Services version 5.0
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SUMMARY
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When you are working with records in a database using Microsoft Active Server
Pages (ASP) for Internet Information Services (IIS), errors may occur when the
text has not been properly formatted for creating a SQL Server clause.
For example, when you create an ASP page to store information posted from an HTML
form to a database, you may see an error message similar to the following:
Microsoft OLE DB Provider for ODBC Drivers (0x80040E14)
[Microsoft][ODBC Microsoft Access Driver] Syntax error (missing operator) in
query expression '<SQL Text>'.
/<path>/<filename.asp>, line <nnn>
MORE INFORMATION
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The error message above occurs when you try to submit a name with an apostrophe,
(for example "O'Malley"), and then insert that name into a SQL Server clause
without first "escaping" it. This can result in a SQL Server clause that
resembles the following:
INSERT INTO Table (txtName VALUES ('O'Malley')
Because SQL Server uses the apostrophe as a text delimiter, the apostrophe in the
name inadvertently signifies an end to the data, which causes the error message
to occur. This text can be "escaped" by using two apostrophes, for example:
INSERT INTO Table (txtName VALUES ('O''Malley')
Obviously, it is not ideal to mandate that all users on a Web site enter two
apostrophes for each desired apostrophe. In addition, when text is later
extracted from a database, certain formatting characters are ignored during HTML
parsing on a client (for example CR-LF, TAB, and so on.)
An ASP Solution:
The following ASP code defines two functions that are designed to handle some
simple parsing of information for input/output of SQL Server data, and can
easily be expanded to incorporate more functionality:
- FixForSQL() parses a string for input to SQL Server
Function FixForSQL(tmpText1)
' define a working variable
Dim tmpText2
' populate our working variable
tmpText2 = tmpText1
' compact a CR-LF sequence as CR to save space
tmpText2 = Replace(tmpText1,vbCrLf,Chr(13))
' replace each apostrophe with two apostrophes
tmpText2 = Replace(tmpText2,Chr(39),String(2,39))
' return the fixed string
FixForSQL = tmpText2
End Function
- FixForHTML() parses a string for output to HTML
Function FixForHTML(tmpText1)
' define a working variable
Dim tmpText2
' populate our working variable
tmpText2 = tmpText1
' replace each CR with a line break tag and CR-LF
tmpText2 = Replace(tmpText2,Chr(13),"<br>" & vbCrLf)
' replace each TAB character with four non-breaking space tags
tmpText2 = Replace(tmpText2,Chr(9),"    ")
' return the fixed string
FixForHTML = tmpText2
End Function
Practical Example - Guestbook Application:
The following steps demonstrate how to use the above functions to create a simple
guestbook application using ASP and a Microsoft Access database:
1. Copy the following ASP code and save it to a folder in your Web site with at
least IIS script access enabled and Copy the following ASP code and save it
to a folder in your Web site with at least IIS "script" access enabled and
Everyone - Change NTFS permissions:
<% @Language="VBScript" %>
<%
Option Explicit
' define our variables
Dim strMethod
Dim strURL
Dim strTitle
Dim strSQL
Dim objCN
Dim objRS
' get some environment variables
With Request
strMethod = UCase(.ServerVariables("REQUEST_METHOD"))
strTitle = UCase(.ServerVariables("SERVER_NAME")) & " Guestbook"
strURL = LCase(.ServerVariables("URL"))
End With
' open our database connection
Set objCN = Server.CreateObject("ADODB.Connection")
objCN.Open "driver={Microsoft Access Driver (*.mdb)};uid=admin;pwd=;" & _
"dbq=" & Server.MapPath(".\guestbook.mdb")
' if the request was a POST then a guest submitted
If strMethod = "POST" Then
Dim strName, strComments
' get the form data and format it
strName = FixForSQL(Request.Form("txtName"))
strComments = FixForSQL(Request.Form("txtComments"))
' build the SQL string
strSQL = "INSERT INTO tblGuestbook (txtName, txtComments)"
strSQL = strSQL & " VALUES ('" & strName & "','" & strComments & "')"
' execute the SQL
objCN.Execute(strSQL)
End If
' create a SQL string to read all guest entries
strSQL = "SELECT * FROM tblGuestbook"
Set objRS = objCN.Execute(strSQL)
%>
<html>
<head><title><%=strTitle%></title></head>
<body>
<h1><%=strTitle%></h1>
<%
' only show the guestbook when there are entries
If Not objRS.EOF Then
%>
<table border="1">
<tr>
<th>Name</th>
<th>Comments</th>
</tr>
<%
' loop through the database
While Not objRS.EOF
With Response
.Write "<tr>" & vbCrLf
.Write "<td>" & FixForHTML(objRS("txtName")) & "</td>" & vbCrLf
.Write "<td>" & FixForHTML(objRS("txtComments")) & "</td>" & vbCrLf
.Write "</tr>" & vbCrLf
End With
objRS.MoveNext
Wend
%>
</table>
<% End If %>
<form action="<%=strURL%>" method="POST">
<table>
<tr>
<td>Name</td>
<td><input type="text" name="txtName"><br>
</tr>
<tr>
<td>Comments</td>
<td><textarea name="txtComments"></textarea><br>
</tr>
<tr>
<td colspan="2"><input type="submit" value="Submit Comments">
</tr>
</form>
</body>
</html>
<%
Function FixForSQL(tmpText1)
Dim tmpText2
tmpText2 = tmpText1
tmpText2 = Replace(tmpText1,vbCrLf,Chr(13))
tmpText2 = Replace(tmpText2,Chr(39),String(2,39))
FixForSQL = tmpText2
End Function
Function FixForHTML(tmpText1)
Dim tmpText2
tmpText2 = tmpText1
tmpText2 = Replace(tmpText2,Chr(13),"<br>" & vbCrLf)
tmpText2 = Replace(tmpText2,Chr(9),"    ")
FixForHTML = tmpText2
End Function
%>
2. Open Microsoft Access, create a new database, and then save it as
Guestbook.mdb in the same folder as the above ASP page.
3. Create a new table in the database named TblGuestbook with the following
fields:
+--------------------------------------+
| Field Name | Data Type | Field Size |
+--------------------------------------+
| txtName | Text | 50 |
+--------------------------------------+
| txtComments | Memo | N/A |
+--------------------------------------+
4. Save the table to the database, and then close Microsoft Access.
Testing the Guestbook Application
1. When you browse the page for the first time, no data is displayed.
2. When information has been submitted, any guestbook entries will appear.
3. Entering apostrophes in names (for example O'Brien, O'Sullivan, and so on) or
contractions (such as don't, can't, and so on) are properly formatted and
stored in the database.
REFERENCES
==========
Microsoft provides programming examples for illustration only, without warranty
either expressed or implied, including, but not limited to, the implied
warranties of merchantability and/or fitness for a particular purpose. This
article assumes that you are familiar with the programming language being
demonstrated and the tools used to create and debug procedures. Microsoft
support professionals can help explain the functionality of a particular
procedure, but they will not modify these examples to provide added
functionality or construct procedures to meet your specific needs. If you have
limited programming experience, you may want to contact a Microsoft Certified
Partner or the Microsoft fee-based consulting line at (800) 936-5200. For more
information about Microsoft Certified Partners, please visit the following
Microsoft Web site:
http://www.microsoft.com/partner/referral/
For more information about the support options that are available and about how
to contact Microsoft, visit the following Microsoft Web site:
http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS
For more information on Microsoft scripting technologies, see the Microsoft
Developer Network web site at the following URL:
http://msdn.microsoft.com/scripting/
Additional query words: iis
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Keywords :
Technology : kbiisSearch kbiis500
Version : :5.0
Issue type : kbinfo
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