Re: [HACKERS] NULL concatenation

Hi

2016-05-12 10:47 GMT+02:00 Sridhar N Bamandlapally <sridhar(dot)bn1(at)gmail(dot)com>:

> 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
>

use function concat
http://www.postgresql.org/docs/9.5/static/functions-string.html

postgres=# select concat('AHOJ', NULL,'XXX');
concat
---------
AHOJXXX
(1 row)

Regards

Pavel

> Please
>
> Thanks
> Sridhar
> OpenText
>
>