Function testing if a string is a number ? - Mailing list pgsql-novice

From Arnaud Lesauvage
Subject Function testing if a string is a number ?
Date
Msg-id 43F9CEDB.8000605@freesurf.fr
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Responses Re: Function testing if a string is a number ?
List pgsql-novice
Hi list !

I am searching for a function that would return true if a string
is a number.
In Access I would have written IsNumeric('mystring'), but this
function does not exist in postgres.
Maybe I am doing this the wrong way actually : I want to fill an
integer field with the values from a varchard field. Some of the
values are not convertible though, so just executing :
UPDATE thetable
SET numfield=varcharfield::int4;
returns an error 'Invalid input syntax for integer "blablabla"'.
My idea was to run :
UPDATE thetable
SET numfield=varcharfield::int4
WHERE IsNumeric(varcharfield);
but maybe there is a better way to achieve this ?

Thanks for your help !

Regards
--
Arnaud


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