Thread: String reverse funtion?
Hello everyone I have to reverse a string like EA;BX;CA to CA;BX;EA. or EA,BX,CA to CA,BX,EA Is there any function to do this? Thanks all! -- View this message in context: http://postgresql.1045698.n5.nabble.com/String-reverse-funtion-tp5773871.html Sent from the PostgreSQL - general mailing list archive at Nabble.com.
Forgot to reply to list. Sorry. Perhaps somebody here knows of an "array_reverse" type function.
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---------- Forwarded message ----------
From: John McKown <john.archie.mckown@gmail.com>
Date: Fri, Oct 11, 2013 at 7:53 AM
Subject: Re: [GENERAL] String reverse funtion?
To: ginkgo36 <ginkgo56@gmail.com>
This would split the string into an array, where each element is delimited with a semi-colon - regexp_split_to_array
Reverse the order of the array with the __missing__ array_reverse function.
Combine back into a string with array_to_string.
But, given the lack of "array_reverse" or something equivalent, I guess you need to "roll your own" function.
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From: John McKown <john.archie.mckown@gmail.com>
Date: Fri, Oct 11, 2013 at 7:53 AM
Subject: Re: [GENERAL] String reverse funtion?
To: ginkgo36 <ginkgo56@gmail.com>
I don't see one. Looks like you will need to write your own function. I got close with a kludge. But I cannot find a base function which will "reverse" the order of elements in an array. If there were such a one, which I will call "array_reverse" in the example, then you could do:
select array_to_string( array_reverse( regexp_split_to_array(string_delimited_with_semicolons,';') ),';');On Wed, Oct 9, 2013 at 10:59 AM, ginkgo36 <ginkgo56@gmail.com> wrote:
Hello everyone
I have to reverse a string like EA;BX;CA to CA;BX;EA. or EA,BX,CA to
CA,BX,EA
Is there any function to do this?
Thanks all!
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This is clearly another case of too many mad scientists, and not enough hunchbacks.
Maranatha! <><
John McKown
John McKown
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This is clearly another case of too many mad scientists, and not enough hunchbacks.
Maranatha! <><
John McKown
John McKown
Hi everyone,
Please hepl me this function:
1. I want to sort string follow anphabet and I used this query:
select string_agg(x, ';') from (select
trim(unnest(regexp_split_to_array('ECD FORM; BODY; PREDILUTED; CHROMO-GENIC;
AUTO;RABBIT; FORMAT',';'))) x order by x) a;
-- result: AUTO; BODY; CHROMOGENIC; ECD FORM; FORMAT; PREDILUTED; RABBIT
-->I expected this rusult
In my database I have a column with alot of rows data. I want that query
become a function to more easy to using. But I can not write a function :(.
please hepl me.
For example, I have column "data_text" with data like this:
Row 1: AUTO; BODY; PREDILUTED; ECD FORM; RABBIT; FORMAT; CHROMOGENIC
Row 2: ECD FORM; BODY; PREDILUTED; CHROMO-GENIC; AUTO; RABBIT; FORMAT
Row 3: FORMAT; ECD FORM; AUTO
Row 3: ANHYDROUS; DENATURED; PREDILUTED; CHROMOGENIC
When I run funtion, the result:
Row 1: AUTO; BODY; CHROMOGENIC; ECD.FORM; FORMAT; PREDILUTED; RABBIT
Row 2: AUTO; BODY; CHROMO-GENIC; ECD FORM; FORMAT; PREDILUTED; RABBIT
Row 3: AUTO; ECD FORM; FORMAT
Row 4: ANHYDROUS; CHROMOGENIC; DENATURED; PREDILUTED
Thank you and best regards,
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ginkgo36 wrote > But I can not write a function :(. please hepl me. > For example, I have column "data_text" with data like this: > Row 1: AUTO; BODY; PREDILUTED; ECD FORM; RABBIT; FORMAT; CHROMOGENIC > Row 2: ECD FORM; BODY; PREDILUTED; CHROMO-GENIC; AUTO; RABBIT; FORMAT > Row 3: FORMAT; ECD FORM; AUTO > Row 3: ANHYDROUS; DENATURED; PREDILUTED; CHROMOGENIC > > When I run funtion, the result: > Row 1: AUTO; BODY; CHROMOGENIC; ECD.FORM; FORMAT; PREDILUTED; RABBIT > Row 2: AUTO; BODY; CHROMO-GENIC; ECD FORM; FORMAT; PREDILUTED; RABBIT > Row 3: AUTO; ECD FORM; FORMAT > Row 4: ANHYDROUS; CHROMOGENIC; DENATURED; PREDILUTED Assuming what you show above is your goal writing such a function is straight-forward. Basically you take your existing SQL and wrap it in a CREATE FUNCTION. The input would be of type "text" as would the output. Inside the function you do all the same split/unnest/trim/string_agg actions as you show above. Start you exploration on the syntax and mechanics here: http://www.postgresql.org/docs/9.3/interactive/xfunc.html While you could use pl/pgsql a simple SQL function is sufficient for your needs. Post a specific question with your attempted "CREATE FUNCTION" if you get stuck. David J. -- View this message in context: http://postgresql.1045698.n5.nabble.com/String-reverse-funtion-tp5773871p5774647.html Sent from the PostgreSQL - general mailing list archive at Nabble.com.