Re: [GENERAL] converting from bytea to integers
On Apr 20, 2009, at 5:23 PM, Daniel Verite wrote: get_byte()? mailtest=> \set e '\'\12\15\107\20\'::bytea' mailtest=> select get_byte(:e,0),get_byte(:e,1),get_byte(:e, 2),get_byte(:e,3); get_byte | get_byte | get_byte | get_byte --+-- +--+-- 10 | 13 | 71 | 16 That's what I ended up with. My first attempts at it were unsuccessful because I did not notice that get_byte uses zero indexing. Earlier in the routine I extracted bytes using substring and just assumed they used the same indexing. They don't. It might be worthy of a documentation note -- it seems easy to miss if you have not used the binary functions before. I generated the integer from the bytes using something like this: b1 = get_byte(p_array, i+3); b2 = get_byte(p_array, i+2); b3 = get_byte(p_array, i+1); b4 = get_byte(p_array, i); val = (b1 << 24) + (b2 << 16) + (b3 << 8) + b4; Thanks, John DeSoi, Ph.D. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] converting from bytea to integers
John DeSoi wrote: I'd like to convert some bytea data to an array of four byte integers (and vice versa). I'm probably missing something obvious, but I don't see an efficient way to generate a 4 byte integer from a bytea string (could be big endian or little endian). get_byte()? mailtest=> \set e '\'\12\15\107\20\'::bytea' mailtest=> select get_byte(:e,0),get_byte(:e,1),get_byte(:e,2),get_byte(:e,3); get_byte | get_byte | get_byte | get_byte --+--+--+-- 10 |13 | 71 | 16 (1 row) Best regards, -- Daniel PostgreSQL-powered mail user agent and storage: http://www.manitou-mail.org -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
[GENERAL] converting from bytea to integers
I'd like to convert some bytea data to an array of four byte integers (and vice versa). I'm probably missing something obvious, but I don't see an efficient way to generate a 4 byte integer from a bytea string (could be big endian or little endian). Converting back to bytea seems easy enough using to_hex. Thanks for any suggestions, John DeSoi, Ph.D. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
