ср, 2 февр. 2022 г. в 09:19, David G. Johnston <david.g.johns...@gmail.com>:
> On Tue, Feb 1, 2022 at 8:15 PM Дмитрий Иванов <firstdis...@gmail.com> > wrote: > >> Why are COLUMN GENERATED ALWAYS AS called "methods" and singled out as a >> separate field type? >> > > This sounds like you are describing something written. Can you provide a > link to where that is? > > Is there a common name in the community for the approach in which the data >> schema is presented as data? >> > It is possible to give a link, but it would require authorization:  Here are the contents of the topic: ==================== Actual code include ALWAYS AS column: CREATE TABLE bpd.schedules_calendar ( id bigint NOT NULL DEFAULT nextval('bpd.work_calendar_id_seq'::regclass), work_date date NOT NULL, work_year integer NOT NULL GENERATED ALWAYS AS (date_part('year'::text, work_date)) STORED, work_month integer NOT NULL GENERATED ALWAYS AS (date_part('month'::text, work_date)) STORED, work_day integer NOT NULL GENERATED ALWAYS AS (date_part('day'::text, work_date)) STORED, day_type bpd.day_type NOT NULL, name_holiday character varying(100) COLLATE pg_catalog."default" NOT NULL DEFAULT 'будний день'::character varying, week40_day interval NOT NULL, week40_month interval NOT NULL, week36_day interval NOT NULL, week36_month interval NOT NULL, week35_day interval NOT NULL, week35_month interval NOT NULL, week24_day interval NOT NULL, week24_month interval NOT NULL, CONSTRAINT work_calendar_pkey PRIMARY KEY (id) ) The code suggested in the studio: CREATE TABLE "bpd"."schedules_calendar" ( "id" BigInt DEFAULT nextval('bpd.work_calendar_id_seq'::regclass) NOT NULL, "work_date" Date NOT NULL, "work_year" Integer DEFAULT date_part('year'::text, work_date) NOT NULL, "work_month" Integer DEFAULT date_part('month'::text, work_date) NOT NULL, "work_day" Integer DEFAULT date_part('day'::text, work_date) NOT NULL, "day_type" "bpd"."day_type" NOT NULL, "name_holiday" Character Varying( 100 ) DEFAULT 'будний день'::character varying NOT NULL, "week40_day" Interval NOT NULL, "week40_month" Interval NOT NULL, "week36_day" Interval NOT NULL, "week36_month" Interval NOT NULL, "week35_day" Interval NOT NULL, "week35_month" Interval NOT NULL, "week24_day" Interval NOT NULL, "week24_month" Interval NOT NULL, PRIMARY KEY ( "id" ) ); DEFAULT VALUE <> GENERATED ALWAYS AS STORED the DEFAULT value is not recalculated when the reference column are changed. is not an identical construction GENERATED ALWAYS AS STORED *reply:* They are in a separate list “Methods”. This approach was used for other databases *long before* generated columns were implemented in PostgreSQL. ==================== > > Which community? There are many ways in which a "data schema [can be] > presented as data". In PostgreSQL there is only a single source of truth > for what the data schema is - the "System Catalogs" [1]. Those tables are > made available to the user in the pg_catalog schema. > > David J. > > I came across a long acronym defining the name of the approach, then I decided that to come up with something fundamentally new is difficult enough. That everything already has a formal name. But I can't find it anymore. I need it to position my solution. Shema - shema Table Entity id | propery1| property2| property3 Shema-data Table Entity id| name Table Property Entity id | id_entity | name| val -- Regards, Dmitry!
