Re: Fwd: String reverse funtion? - Mailing list pgsql-general

From David Johnston
Subject Re: Fwd: String reverse funtion?
Date
Msg-id 1381857922621-5774647.post@n5.nabble.com
Whole thread Raw
In response to Re: Fwd: String reverse funtion?  (ginkgo36 <ginkgo56@gmail.com>)
List pgsql-general
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.


pgsql-general by date:

Previous
From: ginkgo36
Date:
Subject: Re: Fwd: String reverse funtion?
Next
From: Quang Thoi
Date:
Subject: can you do rollback in a trigger function?