Обсуждение: postgres sql help

<div dir="ltr"> hi, i am fairly new in postgresql, so if anyone can help me would be great<br /><br /> if i simply
do:<br/><br /> select ver_no<br /> from version<br /> order by ver_no<br /><br /> the result will be something like
this:<br/><br /> .1.3.1<br /> .1.3.2.5.<br /> .1.4.1.7.12<br /> .1.4.11.14.7.<br /> .1.4.3.109.1.<br /> .1.4.8.66.<br
/><br/> so as you can see first 3 lines are ok, but how to make 1.4.3.109 come before 1.4.11 because the third level
"3"is smaller than "11". i understand they are stored as char so i used split_part function to separate each numbers
between"." in a separate column. but when i try to convert those column into integer, i am getting an error msg saying:
ERROR:invalid input syntax for type numeric: " "<br /><br /> here is my code:<br /><br /> select ver_no, duedate,
status,<br/> to_number(split_part(ver_no, '.', 2), '9999') a,<br /> to_number(split_part(ver_no, '.', 3), '9999') b,<br
/>to_number(split_part(ver_no, '.', 4), '9999') c,<br /> to_number(split_part(ver_no, '.', 5), '9999') d<br /><br /><br
/>from version<br /><br /> order by a,b,c,d<br /><br /> I am not sure if i am heading towards wrong direction but can
someoneplease suggest or give me some other ideas to sort this. <br /><br /> PS: i found some good solution in SQL
Serverbut those commands are not used in postgreSQL.<br /><br />Thanks in advance<br /><br />- James<br /><br /></div> 

James Bond <coolofall@hotmail.com> wrote:

> hi, i am fairly new in postgresql, so if anyone can help me would be great
> 
> if i simply do:
> 
> select ver_no
> from version
> order by ver_no
> 
> the result will be something like this:
> 
> .1.3.1
> .1.3.2.5.
> .1.4.1.7.12
> .1.4.11.14.7.
> .1.4.3.109.1.
> .1.4.8.66.
> 
> so as you can see first 3 lines are ok, but how to make 1.4.3.109 come before
> 1.4.11 because the third level "3" is smaller than "11". i understand they are
> stored as char so i used split_part function to separate each numbers between
> "." in a separate column. but when i try to convert those column into integer,
> i am getting an error msg saying: ERROR: invalid input syntax for type numeric:
> " "
> 
> here is my code:

test=*# select * from o;      t
---------------.1.3.1.1.3.2.5..1.4.1.7.12.1.4.11.14.7..1.4.3.109.1..1.4.8.66.
(6 rows)

Time: 0,262 ms
test=*# select * from o order by split_part(t,'.',2)::int,
split_part(t,'.',3)::int, split_part(t,'.',4)::int;      t
---------------.1.3.1.1.3.2.5..1.4.1.7.12.1.4.3.109.1..1.4.8.66..1.4.11.14.7.
(6 rows)

Time: 0,403 ms


Andreas
-- 
Really, I'm not out to destroy Microsoft. That will just be a completely
unintentional side effect.                              (Linus Torvalds)
"If I was god, I would recompile penguin with --enable-fly."   (unknown)
Kaufbach, Saxony, Germany, Europe.              N 51.05082°, E 13.56889°

In article <SNT102-W49402A41C6B6599F082D35A8E10@phx.gbl>,
James Bond <coolofall@hotmail.com> writes:

> hi, i am fairly new in postgresql, so if anyone can help me would be great
> if i simply do:

> select ver_no
> from version
> order by ver_no

> the result will be something like this:

> .1.3.1
> .1.3.2.5.
> .1.4.1.7.12
> .1.4.11.14.7.
> .1.4.3.109.1.
> .1.4.8.66.

> so as you can see first 3 lines are ok, but how to make 1.4.3.109 come
> before 1.4.11 because the third level "3" is smaller than "11".

The query
 SELECT ver_no FROM version ORDER BY string_to_array(ver_no, '.', '')::int[]

should do what you want.

Harald Fuchs <hari.fuchs@gmail.com> wrote:

>> hi, i am fairly new in postgresql, so if anyone can help me would be great
>> if i simply do:

>> select ver_no
>> from version
>> order by ver_no

>> the result will be something like this:

>> .1.3.1
>> .1.3.2.5.
>> .1.4.1.7.12
>> .1.4.11.14.7.
>> .1.4.3.109.1.
>> .1.4.8.66.

>> so as you can see first 3 lines are ok, but how to make 1.4.3.109 come
>> before 1.4.11 because the third level "3" is smaller than "11".

> The query

>   SELECT ver_no
>   FROM version
>   ORDER BY string_to_array(ver_no, '.', '')::int[]

> should do what you want.

Really neat! :-) For pre-9.1, you have to "ORDER BY
string_to_array(TRIM('.' FROM ver_no), '.')::int[];",
though.

Tim