Re: [HACKERS] [GENERAL] NULL concatenation

[Adam Pearson]

Hello Sridhar,

  Have you tried the 'coalesce' function to handle the nulls?


Kind Regards,

Adam Pearson

________________________________
From: pgsql-general-ow...@postgresql.org <pgsql-general-ow...@postgresql.org> 
on behalf of Sridhar N Bamandlapally <sridhar....@gmail.com>
Sent: 12 May 2016 09:47
To: PG-General Mailing List; PostgreSQL-hackers
Subject: [GENERAL] NULL concatenation

Hi

In migration, am facing issue with NULL concatenation in plpgsql,
by concatenating NULL between any where/position to Text / Varchar, the total 
string result is setting value to NULL


In Oracle:

declare
    txt1 VARCHAR2(100) := 'ABCD';
    txt2 VARCHAR2(100) := NULL;
    txt3 VARCHAR2(100) := 'EFGH';
    txt VARCHAR2(100) := NULL;
begin
  txt:= txt1 || txt2 || txt3;
  dbms_output.put_line (txt);
end;
/

abcdefgh   ===>return value



In Postgres

do $$
declare
    txt1 text := 'ABCD';
    txt2 text := NULL;
    txt3 text := 'EFGH';
    txt text := NULL;
begin
    txt:= txt1 || txt2 || txt3;
    raise notice '%', txt;
end$$ language plpgsql;

NOTICE:  <NULL>  ===> return value


SQL-Server also does same like Oracle

Is there any way alternate we have for same behavior in PostgreSQL

Please

Thanks
Sridhar
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