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追加の列を持つPostgres関数の戻りテーブル

Postgresの初心者はこちら。

テーブルを返すPostgres/plpgsql関数があります。クエリからすべてを返し、加えて作成して返した論理値を返したいのですが。

しかし、周りを検索した後、クエリ内でオンザフライで生成する論理値とともにこのデータを返す方法を理解できないようです。

CREATE OR REPLACE FUNCTION public.sp_user_get_credentials_by_email(email_address character varying)
RETURNS TABLE(credential_id integer, user_id integer, password_hash character varying, password_salt character varying, created_at timestamp without time zone, last_updated_at timestamp without time zone, logical_value_return SMALLINT)
 LANGUAGE plpgsql
AS $function$

DECLARE
sproc_logical_value_return SMALLINT;

BEGIN

-- also want to return logical_value_return along with the query below
-- ex: sproc_logical_value_return = (2)::INT2; how do I add this as a column logical_value_return along with the query below?

  RETURN QUERY
    SELECT
      myapp_users_credentials.credential_id,
      myapp_users_credentials.user_id,
      myapp_users_credentials.password_hash,
      myapp_users_credentials.password_salt,
      myapp_users_credentials.created_at,
      myapp_users_credentials.last_updated_at
    FROM
      myapp_users_credentials
    JOIN myapp_contacts_assoc ON
      myapp_contacts_assoc.user_id = myapp_users_credentials.user_id AND
      myapp_users_credentials.expired_at IS NULL
    JOIN myapp_contacts ON
      myapp_contacts.contact_id = myapp_contacts_assoc.contact_id AND
      myapp_users_credentials.expired_at IS NULL
    WHERE
      myapp_contacts.value = $1 AND
      myapp_contacts.type = 1 AND
      myapp_contacts.is_primary = 1
    LIMIT 1;

  IF NOT FOUND THEN
    RAISE EXCEPTION 'Credentials not found';
  END IF;

END
$function$
postgresqlfunctionsplpgsql
2
Dan

変数をSELECTリストに追加するだけです。

CREATE OR REPLACE FUNCTION public.sp_user_get_credentials_by_email(email_address varchar)
  RETURNS TABLE (credential_id integer
               , user_id integer
               , password_hash varchar
               , password_salt varchar
               , created_at timestamp
               , last_updated_at timestamp
               , logical_value_return smallint) AS
$func$
DECLARE
   sproc_logical_value_return SMALLINT := 2;  -- you can assign at declaration time
BEGIN
   RETURN QUERY
      SELECT uc.credential_id,
             uc.user_id,
             uc.password_hash,
             uc.password_salt,
             uc.created_at,
             uc.last_updated_at
             sproc_logical_value_return  -- just put it in the SELECT list
      FROM   myapp_users_credentials uc
      JOIN   myapp_contacts_assoc    ca ON ca.user_id = uc.user_id      AND uc.expired_at IS NULL
      JOIN   myapp_contacts          c  ON c.contact_id = ca.contact_id AND uc.expired_at IS NULL
      WHERE  c.value = $1
      AND    c.type  = 1
      AND    c.is_primary = 1
      LIMIT  1;

   IF NOT FOUND THEN
      RAISE EXCEPTION 'Credentials not found';
   END IF;
END
$func$  LANGUAGE plpgsql ROWS 1;

テーブルエイリアスを使用して簡略化しました。

関数は定義により単一の行を返すため、値も1回だけ返されます。

RETURNS RECORDの代わりにOUTパラメータと組み合わせたRETURNS TABLEとにかく1行だけを返すため。

CREATE OR REPLACE FUNCTION public.sp_user_get_credentials_by_email(
                 IN  email_address varchar
               , OUT credential_id integer
               , OUT user_id integer
               , OUT password_hash varchar
               , OUT password_salt varchar
               , OUT created_at timestamp
               , OUT last_updated_at timestamp
               , OUT logical_value_return smallint) AS
$func$
BEGIN

   logical_value_return := 2;  -- assign separately or with SELECT list

   SELECT uc.credential_id, uc.user_id, uc.password_hash, uc.password_salt, uc.created_at, uc.last_updated_at
   INTO      credential_id,    user_id,    password_hash,    password_salt,    created_at,    last_updated_at
   FROM   myapp_users_credentials uc
   JOIN   myapp_contacts_assoc    ca ON ca.user_id = uc.user_id      AND uc.expired_at IS NULL
   JOIN   myapp_contacts          c  ON c.contact_id = ca.contact_id AND uc.expired_at IS NULL
   WHERE  c.value = $1
   AND    c.type = 1
   AND    c.is_primary = 1
   LIMIT  1;

   IF NOT FOUND THEN
      RAISE EXCEPTION 'Credentials not found';
   END IF;

END
$func$  LANGUAGE plpgsql;

RETURNS RECORDは冗長ノイズで、この場合は省略できます。

わずかな違い：行が見つからない場合でも、あなたは論理定数を返します。この場合、他の列はNULLになります。詳細：

1
Erwin Brandstetter