Cristóvão Dalla Costa wrote:
> Hi,
>
> I'm using libpq to interface my program to postgresql, and I need to store
> some binary data (around 30-40 bytes per element). I'm not sure of the best
> way to do so, since blobs seem awkward. How would you do it? How would you
> insert it in a text field?
>
> Thanks all,
>
> Cristovao
>
I recommend BYTEA datatype for this. It works in a similar manner to
TEXT, but it is designed for binary data. You will need to escape
certain values on INSERT and unescape on SELECT. See:
http://fts.postgresql.org/db/mw/msg.html?mid=1042181
for a recent post on this.
Hope this helps,
-- Joe
p.s.
Note that in 7.2 (in beta now) there is a function in libpq specifically
for escaping BYTEA input strings (PQescapeBytea -- see fe-exec.c):
/* * PQescapeBytea - converts from binary string to the * minimal encoding necessary to include the string in
anSQL * INSERT statement with a bytea type column as the target. * * The following transformations are applied *
'\0' == ASCII 0 == \\000 * '\'' == ASCII 39 == \' * '\\' == ASCII 92 == \\\\ */
unsigned char *
PQescapeBytea(unsigned char *bintext, size_t binlen, size_t *bytealen)