Blank-padding (was: Oracle buys Innobase)
От | Dean Gibson (DB Administrator) |
---|---|
Тема | Blank-padding (was: Oracle buys Innobase) |
Дата | |
Msg-id | 435979B0.60107@ultimeth.com обсуждение исходный текст |
Ответы |
Re: Blank-padding (was: Oracle buys Innobase)
|
Список | pgsql-sql |
On 2005-10-21 09:47, Tom Lane wrote: > Alex Turner <armtuk@gmail.com> writes: > >> It appears that casting to a char() causes spaces to be stripped (ignored) from the string: >> > mls=# select length('123 '::char(8)); > length > -------- > 3 > (1 row) > > >> I'm not sure about anyone else, but I would personaly consider that a bug? >> > > No, it's a feature, as per extensive discussion some time ago when we made it do that. The general rule is that trailingspaces in a char(n) are semantically insignificant. > > regards, tom lane > I remember that discussion, and I was for the change. However, upon doing some testing after reading the above, I wonder if the blank-stripping isn't too aggressive. I have a CHAR(6) field (say, named Z) that has "abc " in it. Suppose I want to append "x" to Z, with any leading spaces in Z PRESERVED. The following do not work in 8.0.4: select Z || 'x'; select Z::char(6) || 'x'; select Z::varchar(6) || 'x'; select (Z || ' ')::char(6) || 'x'; There are only two ways I've found: select rpad( Z, 6) || 'x'; -- but "rpad" is apparently not a SQL-standard function. select cast (Z || ' ' as varchar(6)) || 'x'; -- hokey but SQL-compliant Is there something I'm missing??? -- Dean
В списке pgsql-sql по дате отправления: