Re: Strict-typing benefits/costs - Mailing list pgsql-general

From Tom Lane
Subject Re: Strict-typing benefits/costs
Date
Msg-id 20588.1203180440@sss.pgh.pa.us
Whole thread Raw
In response to Re: Strict-typing benefits/costs  (Ken Johanson <pg-user@kensystem.com>)
Responses Re: Strict-typing benefits/costs
List pgsql-general
Ken Johanson <pg-user@kensystem.com> writes:
> select 5<'6' -> true
> select 5>'6' -> false
> select 15<'60' -> true
> select 15>'60' -> false

These examples miss the point, because they'd give the same answer
whether you think the values are text or integer.  Consider instead
these cases:

regression=# select 7 > '60';             -- int > int
 ?column?
----------
 f
(1 row)

regression=# select '7' > '60';           -- text > text
 ?column?
----------
 t
(1 row)

regression=# select 7 > '08';             -- int > int
 ?column?
----------
 f
(1 row)

regression=# select '7' > '08';           -- text > text
 ?column?
----------
 t
(1 row)

All of a sudden it seems much more important to be clear about
what data type is involved, no?

> Numbers and datetime in sql have exactly prescribed standard char
> representations (even if others dbs don't use them for datetimes).

See the datestyle parameter before you maintain that Postgres
should assume that.

            regards, tom lane

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