Thread: regexp_matches for digit

On 7/9/2015 11:24 AM, Ramesh T wrote:
> Hi,
>            in oracle regexp_like(entered
> date,'[[:digit:]]{4}-[[:digit:]]{2}-[[:digit:]]{2}','i')
>
> for postgres i have regexp_matches ,But i need how to match [:digit:] in
> postgres when we pass date..?
> any help

\d

per:
http://www.postgresql.org/docs/devel/static/functions-matching.html

# select 1 where '1234-56-78' ~ '\d{4}-\d{2}-\d{2}';
  ?column?
----------
         1
(1 row)

> Hi,
>           in oracle regexp_like(entered
> date,'[[:digit:]]{4}-[[:digit:]]{2}-[[:digit:]]{2}','i')
>
> for postgres i have regexp_matches ,But i need how to match [:digit:] in
> postgres when we pass date..?
> any help

[:digit:] is Posix syntax, supported by Postgres.

Looks good to me:

graal=# select regexp_matches('2015-07-09',
'[[:digit:]]{4}-[[:digit:]]{2}-[[:digit:]]{2}','i');
 regexp_matches
----------------
 {2015-07-09}
(1 row)

graal=# select regexp_matches('2015-x7-09',
'[[:digit:]]{4}-[[:digit:]]{2}-[[:digit:]]{2}','i');
 regexp_matches
----------------
(0 rows)

What do you need, exactly?

Bye,
Chris.

Hi,

          in oracle regexp_like(entered date,'[[:digit:]]{4}-[[:digit:]]{2}-[[:digit:]]{2}','i')

for postgres i have regexp_matches ,But i need how to match [:digit:] in postgres when we pass date..?

any help

But trying to truly validate dates purely with a regex is more effort than I'm willing to put in. I don't recall where I ran across this snippet but it creates a function that ensures that the date is acceptable to PostgreSQL without raising an error:


CREATE OR REPLACE FUNCTION is_valid_date(text)
   RETURNS bool AS
'
begin
  return case when $1::date is null then false else true end;
exception when others then
  return false;                                               
end;
'
LANGUAGE 'plpgsql' VOLATILE;

Cheers,
Steve