Question

I would like to do something like :

update cli_pe set nm_cli_espace_client = 9 || nm_cli_espace_client
 where nm_cli_pe = 7006488 

nm_cli_espace_client is numeric(0,8).

How to make it easy?

Answer 1

UPDATE cli_pe
   SET nm_cli_espace_client = '9' || CAST(nm_cli_espace_client AS text)
 WHERE nm_cli_pe = 7006488;

If you need a resulting number, then CAST back the result:

... SET nm_cli_espace_client =
      CAST('9' || CAST(nm_cli_espace_client AS text) AS integer)

Your question is identical to this one: concat two int values in postgresql