Insert binary file in SQLite database with Python

Question

I trying to write a simple Python script that inserts .odt documents into an SQLite database. Here what I have so far, but it doesn't seem to work:

f=open('Loremipsum.odt', 'rb')
k=f.read()
f.close()
cursor.execute="INSERT INTO notes (note) VALUES ('%s')" %(sqlite.Binary(k))
cursor.close()
conn.close()

I don't get any error messages, but as far as I can see the record is not inserted. What am I doing wrong? Also, how can I extract the stored document back? Thanks!

Answer 1

Not sure what is that sqlite.Binary you're using, but, anyway, here's a working example:

import sqlite3

# let's just make an arbitrary binary file...
with open('/tmp/abin', 'wb') as f:
  f.write(''.join(chr(i) for i in range(55)))
# ...and read it back into a blob
with open('/tmp/abin', 'rb') as f:
  ablob = f.read()

# OK, now for the DB part: we make it...:
db = sqlite3.connect('/tmp/thedb')
db.execute('CREATE TABLE t (thebin BLOB)')
db.execute('INSERT INTO t VALUES(?)', [buffer(ablob)])
db.commit()
db.close()

# ...and read it back:
db = sqlite3.connect('/tmp/thedb')
row = db.execute('SELECT * FROM t').fetchone()
print repr(str(row[0]))

When run with Python 2.6, this code shows, as expected and desired: '\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !"#$%&\'()*+,-./0123456'

Note the need to use buffer to insert the blob, and str to read it back as a string (since it uses the buffer type as a result as well) -- if you're just going to write it to disk the latter passage would not be needed (since the write method of files does accept buffer objects just as well as it accepts strings).

Answer 2

Problems:

1. You didn't show the full code that you ran. You shouldn't leave answerers guessing what things like sqlite.Binary(k).

2. Fundamental problem: You didn't commit your transaction. Use conn.commit() before conn.close().