[Python-Dev] BLOBs in Pg

Steve Holden steve at holdenweb.com
Fri Apr 10 01:56:25 CEST 2009


Oleg Broytmann wrote:
> On Thu, Apr 09, 2009 at 04:42:21PM -0400, Steve Holden wrote:
>> If I can't pass a 256-byte string into a BLOB and get it back without
>> anything like this happening then there's *something* in the chain that
>> makes the database useless.
> 
> import psycopg2
> 
> con = psycopg2.connect(database="test")
> cur = con.cursor()
> cur.execute("CREATE TABLE test (id serial, data BYTEA)")
> cur.execute('INSERT INTO test (data) VALUES (%s)', (psycopg2.Binary(''.join([chr(i) for i in range(256)])),))
> cur.execute('SELECT * FROM test ORDER BY id')
> for rec in cur.fetchall():
>    print rec[0], type(rec[1]), repr(str(rec[1]))
> 
> Result:
> 
> 1 <type 'buffer'> '\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 !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff'
> 
>    What am I doing wrong?
> 
> Oleg.

Corresponding with me, probably. Thank you Oleg. I feel suddenly saner
again.

regards
 Steve
-- 
Steve Holden           +1 571 484 6266   +1 800 494 3119
Holden Web LLC                 http://www.holdenweb.com/
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