For some time i uses postgreSQL databases through VB.NET/odbc and I'm very satisfied with that.
But till today I was never successfully save a picture to byteA field of my database.

Most examples I found on net have some INSERT advices but I can't find an UPDATE (for replace pictures) example.

In short, this is how I try, unsuccessfully:
Using pgCommand As OdbcCommand = New OdbcCommand("UPDATE " & Tablename & " SET(?,?) WHERE record=" + RecNum, pgConnection)  
pgCommand.Parameters.AddWithValue("@RecPicture", pgByteA)
Please any advice how to do that properly.