how to store binary file data to a database blob

[Benjamin Niemann]

> I'd like to read the contents of a file into memory.  The problem is 
> that this file is binary.  I then want to store the whole thing in 
> memory to a database as a blob.
> I have no problem reading from a file:  I did this:
> 
> import os
> f = open('/bin/ls' , 'r+b')
> data = f.read()
> f.close()
> 
> How do I place that in a blob?   If I concatenate this to a sql string, 
> how will the database sql parser know where my data string ends, knowing 
> that my data string could contain lots of ' and " and other little 
> things in it. ???
> 
> storeString = "insert into mytable (filedata) values ( %s ) " % data
> 
> Does that look right?  I don't think it would execute correctly.
This probably won't work... Try this (assuming you are working with a 
Python DB API compatible database class):

cursor.execute("insert into mytable (filedata) values ( %s ) ", data)

This will let the database class replace %s by your data, including all 
required escaping stuff - in contrast to a 1:1 string replacment when 
using the % operator. This works at least for arbitrary strings (and 
that's the way to handle strings, if you don't like SQL injections ;)
But I never tried this with blobs - perhaps they need some special 
treatment (thinking e.g. of laaarge files)...