Re: Two seperate problems with libpq - arrays and bytea edit

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: Two seperate problems with libpq - arrays and bytea edit
Дата
Msg-id 5157.1116096673@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Two seperate problems with libpq - arrays and bytea edit  (Teunis Peters <teunis@wintersgift.com>)
Список pgsql-interfaces
Teunis Peters <teunis@wintersgift.com> writes:
> I'm trying to figure out how to read from and write to bytea values and 
> array (specifically "text[2][]" for a key:value 'dictionary') and 
> cannot figure it out.

Well, since you are asking for binary output format from PQexecParams,
the bytea result is going to just be raw binary data: you should not be
trying to apply PQunescapeBytea to it.  I don't know the notation you
are using well enough to tell what's wrong with your second variant.

> Arrays I'm completely lost - I haven't a clue what the format would be.

Looking at array_send, the binary wire format is
number of dimensions (int4)flags (int4)element type id (Oid)for each dimension:    dimension length (int4)    dimension
lowersubscript bound (int4)for each array element:    element value, in the appropriate format
 

The "flags" are currently always 0, and I would recommend punting if
you see something else, since something else would very possibly
indicate a change in the wire format.

Don't forget that the wire format for integers is network byte order
(ie, big-endian).
        regards, tom lane


В списке pgsql-interfaces по дате отправления:

Предыдущее
От: Teunis Peters
Дата:
Сообщение: Two seperate problems with libpq - arrays and bytea edit
Следующее
От: Volkan YAZICI
Дата:
Сообщение: Network Byte Order Coercion