On Fri, Jan 7, 2011 at 11:44 AM, Iustin Pop
Hi all,
It seems that (at least) the postgresql bindings do not allow pure binary data.
I have a simple table:
debug=# create table test (name bytea);
byteas seems to be the backing type on the DB side for bytestrings.
and then I run this:
import Database.HDBC.PostgreSQL import Database.HDBC import Data.ByteString
main = do db <- connectPostgreSQL "dbname=debug" stmt <- prepare db "INSERT INTO test (name) VALUES($1)" execute stmt [toSql $ pack [0]] execute stmt [toSql $ pack [65, 0, 66]] commit db
What happens is that the inserted string is cut-off at the first NULL value: the first row is empty, and the second row contains just "A".
http://www.postgresql.org/docs/8.4/static/datatype-binary.html says:
“When entering bytea values, octets of certain values must be escaped (but all octet values can be escaped) when used as part of a string literal in an SQL statement. In general, to escape an octet, convert it into its three-digit octal value and precede it by two backslashes”, and continues to list that NULL should be quoted as E'\\000'. However, I find no such quoting in the HDCB.Postgresql sources.
Anyone else stumbled on this?
thanks, iustin
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Yes, I had a bug reported in persistent-postgresql that I traced back to this bug. I reported the bug, but never heard a response. Frankly, if I had time, I would write a low-level PostgreSQL binding so I could skip HDBC entirely. Michael