I'm having problems pulling BLOB data from a mysql db and displaying it in a web browser. I can query the db just fine and return text data. However, the BLOB shows up as "Y0ya" instead of the actual picture. Here's the simple code:
<CFQUERY NAME="agents" DATASOURCE=
"alaweb2">
SELECT * FROM tbl_Files<CFQUERY>
<head>
<title>Agent Qry.</title>
</head>
<body>
<h1>Output From DB</h1>
<CFOUTPUT QUERY="agents">
#id_files#<BR>
#bin_data#<BR>
#description#<BR>
#filename<BR>
#filesize<BR>
#filetype#<BR>
#owner#<BR>
#prop_num#<BR>
</CFOUTPUT>
</body>
</html>
All text data comes in just like I want it to. I know that BLOBs are 0's and 1's streaming in RAW format from the DB. I just don't know how to make CF display them. Please advise. This is the only problem that's holding this project up.
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BLOBs are a poor ways to store files. Think about how much work your DB has to do just to transfer all that binary data that the web servers file system can do much more quickly. In terms of file managemant, simply creating a directory structure might help out. For instance, creating a folder for each specific user based on something like a an identity field. For every picture they upload, check to see if their unique folder is created. If not, then create it. Then you store the file in their unique folder then put a entry in your images table with the userid and filename. Now you just have to query the userid and filename to display the image using something like this:
<cfoutput query="qryImages">
<img alt="" src="#qryImages.userid#/#q
</cfoutput>
BLOBs are bad. Stay away from them. Especially since Cold Fusion doesn't have a lot of support for binary data formats. But if you must, ASP and PHP can send binary data directly to the browser without having to save the file locally first like in Cold Fusion.
O.k., I say I convert to the /dir/picdir method. What would be some of the security precautions that I would need to take to assure that no one could access the /picdir/ w/o running the .cfm script? Couldn't web users put http://www.domainname.com/
You could save the pictures in a directory outside your web root then you could use a modified version of Anand's example of using the CFCONTENT tag to write out the image. It would help to add a unique identifier to your picture table. Then you could create a page called displayimage.cfm that would take in one field in the querystring called ImageID then include the following code inside the page:
<CFIF IsDefined("URL.ImageID") EQ True>
<!--- Pull out the UserID from the session to use in the query. --->
<CFLOCK name="lckTestSecurity" scope="session" timeout="15" type="readonly">
<CFSET OwnerID = SESSION.UserID>
</CFLOCK>
<!--- Use the ImageID and UserID to query the database. This insures that only the user who uploaded the file can see it. --->
<CFQUERY name="qryImages">
SELECT *
FROM ImagesTable
WHERE ImageID = <CFQUERYPARAM cfsqltype="cf_sql_integer"
AND UserID = <CFQUERYPARAM cfsqltype="cf_sql_integer"
</CFQUERY>
<CFIF qryImages.RecordCount EQ 1>
<!--- The request is a valid image request so show them the image. --->
<CFCONTENT type="image/jpeg" file="secure_folder_outsid
<CFELSE>
<!--- The Image does not exist or the user requesting it does not have rights to view it so give them a proper error image. --->
<CFCONTENT type="image/jpeg" file="secure_folder_outsid
</CFIF>
<CFELSE>
<!--- An image ID was not supplied. I would create an image that has the wording invalid imageid and display it --->
<CFCONTENT type="image/jpeg" file="secure_folder_outsid
</CFIF>
For this example you would need to create two images that display error messages. But this would keep your picture directory hidden as it would be outside the web root requiring this displayimage.cfm file to pull in the file and display it. It also performs the security check of only the owner of the image can see it. The example above was written quickly and will probably need to be debugged but is close enough. Hope this helps.
Business Accounts
Answer for Membership
by: anandkpPosted on 2003-04-18 at 22:43:00ID: 8357656
<!--- ==========================
<!--- the form page - test.cfm --->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE>Untitled</TITLE>
</HEAD>
<BODY>
<FORM name="test" method="post" action="test_action.cfm" enctype="multipart/form-da
<INPUT type="File" name="myFile">
<INPUT type="Submit">
</FORM>
</BODY>
</HTML>
/*
This file takes the file selected in the previous template, and inserts it into the database.
(Need to insert a DSN, username/password ;-)
*/
<!--- the insert page test_action.cfm --->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE>Untitled</TITLE>
</HEAD>
<BODY>
<CFFILE ACTION="ReadBinary" FILE="#MyFile#" VARIABLE="aBinaryObj">
<CFIF isBinary(aBinaryObj)>
<CFSET base64 = toBase64(aBinaryObj)>
<CFELSE>
<CFABORT showerror="The file doesnt seem to be a binary file">
</CFIF>
<CFQUERY datasource="" username="" password="">
INSERT INTO PHOTOS(PERSON_ID, PHOTO)
VALUES (1,<CFQUERYPARAM VALUE="#base64#" CFSQLType="CF_SQL_CLOB">)
</CFQUERY>
</BODY>
</HTML>
/*
This file pulls the image from the database, and then moves to result.cfm, which is where the image "appears"
(Again, supply DSN username/password)
*/
<!--- the Select doc page --->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE>Untitled</TITLE>
</HEAD>
<BODY>
<CFQUERY name="getImg" datasource="" username="" password="">
SELECT PHOTO FROM PHOTOS WHERE PERSON_ID = 1
</CFQUERY>
<CFFILE action="WRITE" file="#GetDirectoryFromPat
<CFLOCATION url="result.cfm">
</BODY>
</HTML>
/*
This is the image from the database!
*/
<CFCONTENT type="image/jpeg" file="#GetDirectoryFromPat
<!--- ==========================