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#1 (**permalink**) 04-09-2008, 05:58 AM

Just something I was curious about - is there any
difference at all between "character varying" (in the
SQL spec) without a length specified and "text" (not
in the SQL spec)?

Thanks,
CSN

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#2 (**permalink**) 04-09-2008, 05:58 AM

CSN <cool_screen_name90001@yahoo.com> writes:
> Just something I was curious about - is there any
> difference at all between "character varying" (in the
> SQL spec) without a length specified and "text" (not
> in the SQL spec)?

The SQL standard doesn't allow "character varying" without a length spec.

But yeah, in Postgres they're essentially the same thing.

regards, tom lane

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#3 (**permalink**) 04-09-2008, 06:00 AM

I thought a char field was supposed to return a padded string, and varchar
was supposed to return a non-padded string?

I just checked though:

create table test (
stuff char(10)
);

insert into test values ('foo');

select stuff || 'lemon' from test;

This returns 'foolemon', not 'foo lemon' as I would have expected.

Alex Turner
NetEconomist

On 9/15/05, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> CSN <cool_screen_name90001@yahoo.com> writes:
> > Just something I was curious about - is there any
> > difference at all between "character varying" (in the
> > SQL spec) without a length specified and "text" (not
> > in the SQL spec)?
>
> The SQL standard doesn't allow "character varying" without a length spec.
>
> But yeah, in Postgres they're essentially the same thing.
>
> regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match
>

#4 (**permalink**) 04-09-2008, 06:00 AM

On Mon, 2005-09-19 at 12:54, Alex Turner wrote:
> I thought a char field was supposed to return a padded string, and
> varchar was supposed to return a non-padded string?
>
> I just checked though:
>
> create table test (
> stuff char(10)
> );
>
> insert into test values ('foo');
>
> select stuff || 'lemon' from test;
>
> This returns 'foolemon', not 'foo lemon' as I would have
> expected.
>
> Alex Turner
> NetEconomist
>
> On 9/15/05, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> CSN <cool_screen_name90001@yahoo.com> writes:
> > Just something I was curious about - is there any
> > difference at all between "character varying" (in the
> > SQL spec) without a length specified and "text" (not
> > in the SQL spec)?
>
> The SQL standard doesn't allow "character varying" without a
> length spec.
>
> But yeah, in Postgres they're essentially the same thing.
>
> regards, tom lane
>
> ---------------------------(end of
> broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your
> desire to
> choose an index scan if your joining column's datatypes
> do not
> match
>

That's because || is a text operator, not a char operator here. So,
what's really happening is:

select cast(charfield as text)||cast(textfield as text)

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character varying == text?