Re: Storing JPG's as BLOB data type

[Scott Klement <midrange-l@xxxxxxxxxxxxxxxx>]

hi Roger,

The advantage (pros) of using a BLOB you already know:  It keeps things 
more organized. You can store the picture in the same record with the 
other relevant details, delete/purge them as one record, and never worry 
about your database & IFS directories getting out of sync.

The disadvantage (cons) is that the JPG data is only available via SQL. 
So you can't simply have a web page that refers directly to the JPG via 
an <img> tag... instead, a program/script has to run that will load the 
JPG from the file.  Likewise, if you have a PC program that you're using 
to browse the IFS, you won't find your images, you'll have to extract 
them from the database first.

You don't have to "convert" the data (it's still the same exact stream 
of bytes) to put it into a BLOB...  but you'll need to copy it from the 
STMF into the BLOB of the record.

This should be pretty trivial to do if you already have a list of the 
filenames in a database file.  The pseudocode looks like this:

1) Read a filename
2) Fill in a BLOB_FILE structure with the filename, filename length, and 
file option.
3) Run an INSERT (or UPDATE) SQL statement to add it to the database
4) Delete the IFS file (assuming insert/update was successful)
5) Repeat steps 1-4 until there are no more filenames to process.

It really wouldn't be a big deal to write and run this program as a 
one-time-shot to get the data into the database.


On 7/6/2011 4:24 PM, Harman, Roger wrote:
> I've been considering changing the data storage on one of our apps
> that uses images.  Currently, we store the images as JPG's and use a
> file name reference in the database record.  I was thinking about
> storing them as BLOB's so the image always stays with the other data
> or goes away when the record is deleted.
>
> Has anyone done anything similar and any considerations (pro&  con) I
> should be aware of?  Also, any references to converting several
> thousand JPG's to blob (and vice versa) would be appreciated.
>
>
> Thanks.