MYSQL and use of blobs

[Raaijmakers, Vincent (GE Infrastructure)]

It is the first time that I use blobs in mysql.
Please help me out here.....

Using MSSQLdb and python 2.3.4 I was surprised to see how my information was stored in the blob.
My goal is to store JPG images in the blob. Well, it stores it but as a string of bytes:
'x0dx0fxffxa3......'

So, when reading back that information into my python environment, it seems that I need to translate the value back to the original binary format?

Sniffed for an hour in the asciibin, binhex and other modules...

Somebody with experience to help me out here?
Is there something fundamentally that I do wrong here? In storage, retreiving...

Any help would be very appreciated.
Vincent

 

[Mark Hertel]

It is the first time that I use blobs in mysql Please help me out .
here.... .

Using MSSQLdb and python 2.3.4 I was surprised to see how my
information was stored in the blob. My goal is to store JPG
images in the blob. Well, it stores it but as a string of bytes:
'x0dx0fxffxa3......'

So, when reading back that information into my python environment, it
seems that I need to translate the value back to the original binary
format?

Sniffed for an hour in the asciibin, binhex and other modules...

Somebody with experience to help me out here? Is there something
fundamentally that I do wrong here? In storage, retreiving...

Any help would be very appreciated. Vincent

I didn't have to do anything more fancy than read the information
from the database and write it as a binary file.

SQL table:

create table if not exists audioImage(id int auto_increment primary key,
problemID int, realName varchar(250), shortName varchar(250), data
longblob


Storing the images/audio files:
fileData = open(fileName, 'rb').read()
fileData = zlib.compress(fileData,9)
fileData = db.escape_string(fileData)
query = "insert into audioImage(problemID, data,
shortName) values(%d, '%s', '%s')" % (problemID,
fileData, file)

Retrieving the stored images or audio files:
self.db.execute('select shortName,data from audioImage where id=%d' % int(id))
result = self.db.getAll()
fileName = result[0][0]
retResult = result[0][0]
realData = zlib.decompress(result[0][1])
open(fileName,'wb').write(realData)


This deposits the audio/image files in the current directory where
the program picks them up and uses them. There wasn't anything special
to do, other than retrieving and decompressing the data.


--Mark Hertel