Re: Best way to insert a row with two columns having the value based on the same argument generated by another postgres function.

["David G. Johnston" <david.g.johnston@xxxxxxxxx>]

On Thu, Jul 7, 2016 at 2:56 AM, Silk Parrot <silkparrot@xxxxxxxxx> wrote:

Hi,

 

   I am trying to build a user database. The steps for creating a new user are:

1. Use gen_salt to create a salt.

2. Compute the hash based on the salt and password and store both the hash and the salt into a new row.

The pl/pgsql would look like this:

CREATE OR REPLACE FUNCTION system.create_enduser(IN emailArg TEXT, IN passwordArg TEXT, IN nicknameArg TEXT, IN roundsArg int) RETURNS TEXT AS
$$
#print_strict_params on
DECLARE
    salt TEXT;
    inserted_uuid TEXT;
BEGIN
    salt := public.gen_salt('bf', roundsArg);
    INSERT INTO system.enduser (email, password_hash, password_salt, nickname, user_state) VALUES (emailArg, public.crypt(passwordArg, salt), salt, nicknameArg, 'REGISTERED') RETURNING uuid into inserted_uuid;
    RETURN inserted_uuid;
END
$$
  LANGUAGE 'plpgsql' VOLATILE
;

Is there a way to do this in a single SQL statement without using a function? One way I can think of is using trigger, but that still requires another setup.

Appreciate any help.

​WITH salt_value AS (

SELECT gen_salt('bf', roundsArg) AS value_of_salt

)​

 

​INSERT INTO system.enduser

SELECT emailArg, crypt(passwordArg, value_of_salt), value_of_salt, ...

FROM salt_value​;

You can probably lose the WITH and just make a subquery FROM...

David J.