[Pypgsql-users] Inserting BYTEA values

[Sidney C. <sid...@ji...>]

Dear all,

I have problems inserting 'BYTEA'-type values using PgSQL.

The code fragment given below fails to do what I want; as is, it gives  
me a 'libpq.OperationalError: ERROR: invalid byte sequence for  
encoding "UTF8"'.

I've tried many variations: wrapping 'data' as a PgSQL.PgBytea  
instance; using PgSQL.QuotePgBytea(); setting the encoding in the  
PgSQL.connect() call ...

However, I have not succeeded in doing what the code below intends to  
do: inserting a BYTEA field into the database comprising all 256  
possible byte values in sequence.

What am I doing wrong? Should I not use the Python 'str' type for this  
perhaps? I've checked the docs but I have been unable to find a  
solution.

Any help would be greatly appreciated.

Sidney

##############

from pyPgSQL import PgSQL

# open the database; make a cursor

connection = PgSQL.connect(database="testdb")
cursor = connection.cursor()

# Suppose I have a 256-byte string like this,
# containing all 256 possible byte values:

data = str.join("", [chr(i) for i in range(0, 256)])

# And I want to insert this into a 'bintab' table
# that has a 'data' field of PostgreSQL type 'BYTEA':

query = "INSERT INTO bintab(data) VALUES (%s);"
params = (data, )

# Now execute this (THIS WILL THROW AN EXCEPTION)

cursor.execute(query, params)

# Say goodbye

cursor.close()
connection.close()

##############