postgresql - Postgres query to check a string is a number

Question

Can anyone tell me the query to check whether a string is a number(double precision). It should return true if the string is number. else it should return false.

consider :

       s1 character varying;
       s2 character varying;

       s1 ='12.41212' => should return true
       s2 = 'Service' => should return false

question from:https://stackoverflow.com/questions/19975257/postgres-query-to-check-a-string-is-a-number

Answer 1

I think the easiest way would be a regular expression match:

select '12.41212' ~ '^[0-9.]+$'
=> true

select 'Service' ~ '^[0-9.]+$'
=> false