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