Bin grad am Bl�ttern im W2K Resource Kit und fand diesen Ansatz.
Vielleicht hilft es was
--
Viele Gr��e
Hubert Daubmeier
Retrieving Image Data
Images (as with long bodies of text) are stored in a database as BLOB
fields. Because of the added overhead for the DBMS, retrieving images
from a database is slower than referencing an image URL on disk, so
whether or not you store images in a database depends on the
requirements of your application. You can retrieve image data with ADO
by using the GetChunk method of the Field object. This method requires
that you specify the number of bytes or characters that you wish to
retrieve.
It takes two files working together to retrieve multiple images on the
same page. The main file, which contains HTML formatting and IMAGE tags,
requires the use of a separate ASP file to perform the actual image
query. The secondary ASP file, Image.asp, retrieves the requested image,
and returns it as a binary object in the HTTP response using a MIME
content type of �image/gif.� The following is the source for Image.asp:
<%@ LANGUAGE=JScript EnableSessionState=False %>
<%
var ID, rs, fld, cBytes
ID = Request.QueryString("ID");
if (ID + "" != "undefined") {
rs = Server.CreateObject("ADODB.Recordset");
rs.Filter = "ImageID=" + ID; //--- Search criteria
rs.Open ("Images", Application("ConnectionString"),
adOpenForwardOnly, adLockReadOnly, adCmdTableDirect);
if (!rs.EOF) {
fld = rs("ImageData"); //Get field reference.
cBytes = fld.ActualSize; //Determine size.
//Return raw binary image data as "image/jpeg" MIME type.
Response.ContentType = "image/jpeg";
Response.BinaryWrite(fld.GetChunk(cBytes));
}
else {
Response.Write("Image '" + ID + "' not found.");
}
rs.Close();
}
else {
Response.Write("No ID");
}
%>
In the main file, images stored in the database can now be retrieved
using the image ID as a URL parameter to Image.asp, like this:
<IMG SRC="./image.asp?ID=<%=ImageID%>">
When you use a firehose cursor, there isn�t a good way to discover the
size of a BLOB field before you read it. If you must use a firehose
cursor, consider maintaining a separate column in the database table
that stores the image�s size in bytes. Otherwise, you could call the
GetChunk method repeatedly until it returns nothing. Alternatively, if
you think that the image will fit into available memory, simply use the
Value property to retrieve the data all at once.
-----Original Message-----
From: TUX [mailto:[EMAIL PROTECTED]]
Sent: Sunday, September 09, 2001 6:07 PM
To: ASP Datenbankprogrammierung
Subject: [aspdedatabase] Felder werden nicht ausgegeben
Hallo,
nachdem importieren von Daten einer Acces2000DB in SQL7 werden
Memofelder nicht mehr in der Asp-Seite ausgegeben. Sie bleiben einfach
leer. Im Enterprise-Manager von SQL7 sind diese wohl aber noch
vorhanden. Was ist hier zu tun? Reorganisieren hat leider nichts
gebracht.
Viele Gr��e
TUX
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