Обсуждение: bytea question

PG 8.4.0 running on Mac OS 10.6.1

Could anyone tell me why the bytea datatypes seems to like some bytes better
than others?

testdb=# create table byteatest(blob bytea);
CREATE TABLE
testdb=# insert into byteatest (blob) values (E'\\007');
INSERT 0 1
testdb=# insert into byteatest (blob) values (E'\\008');
ERROR:  invalid input syntax for type bytea
LINE 1: insert into byteatest (blob) values (E'\\008');

Or also:

testdb=# SELECT E'\\001'::bytea;
 bytea
-------
 \001
(1 row)

testdb=# SELECT E'\\008'::bytea;
ERROR:  invalid input syntax for type bytea
LINE 1: SELECT E'\\008'::bytea;

As far as I can see i followed the escaping rules given in

http://www.postgresql.org/docs/current/static/datatype-binary.html

Thanks,

Maximilian Tyrtania

On Mon, 28 Sep 2009, Maximilian Tyrtania wrote:

> testdb=# create table byteatest(blob bytea);
> CREATE TABLE
> testdb=# insert into byteatest (blob) values (E'\\007');
> INSERT 0 1
> testdb=# insert into byteatest (blob) values (E'\\008');
> ERROR:  invalid input syntax for type bytea
> LINE 1: insert into byteatest (blob) values (E'\\008');
>
> Or also:
>
> testdb=# SELECT E'\\001'::bytea;
>  bytea
> -------
>  \001
> (1 row)
>
> testdb=# SELECT E'\\008'::bytea;
> ERROR:  invalid input syntax for type bytea
> LINE 1: SELECT E'\\008'::bytea;
>
> As far as I can see i followed the escaping rules given in
>
> http://www.postgresql.org/docs/current/static/datatype-binary.html

From that:

"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."

008 isn't a valid octal value, you'd want 010 to represent 8.