Re: viewing the original (chrnological) order of entered
От | Ron Johnson |
---|---|
Тема | Re: viewing the original (chrnological) order of entered |
Дата | |
Msg-id | 1055273358.9312.21.camel@haggis обсуждение исходный текст |
Ответ на | Re: viewing the original (chrnological) order of entered (Csaba Nagy <nagy@ecircle-ag.com>) |
Список | pgsql-general |
On Tue, 2003-06-10 at 05:06, Csaba Nagy wrote: > No, at least not as you expect it. SQL returns the found records in > random order except for the explicit "order by" clause. So if you want a Following up on this: the reason it does not happen is because the relational algebra that underpins relations DBMSs acts on un-ordered sets. This is different from old pseudo-RDBMSs like dBASEIII in which you had to explicitly access rows by number. > chronological order, you have to supply some ordering fields to the > order by clause. This could be achieved easily by normalizing your > table, i.e. create a table like: > create table ages ( > age_id smallint primary key, > sort_order smallint, > age_name varchar(100) > ); > insert into ages values (1, 10, 'childhood'); > insert into ages values (2, 20, 'high school'); > insert into ages values (3, 30, 'univesrity'); > > NOTE: leave gaps in the sort order to accommodate for later insertions. > > Then in the original table replace the names with age_id, and use a join > on the 2 tables, sorting by original_table.person_id, ages.sort_order. > > HTH, > Csaba. > > > On Tue, 2003-06-10 at 11:50, Sven Van Acker wrote: > > Hi > > > > > > > > I've the following problem: > > > > > > > > I have a 2-column table with columns "person_id"(int4) and "phase"(text). > > > > > > > > When I entered the following records in a chronological fashion: <1, "high > > school">; <1, "childhood"> and <2, "university">; > > > > > > > > > > > > I requested the following select-statement. > > > > > > > > SELECT person_id, phase FROM life ORDER BY person_id > > > > > > > > And found the tuple <1, "childhood"> before the tuple <1, "high school">. > > > > > > > > I want to view the chronological order of my entries, but ordered by > > person_id. > > > > Is this possible in postgresql? > > -- +-----------------------------------------------------------+ | Ron Johnson, Jr. Home: ron.l.johnson@cox.net | | Jefferson, LA USA http://members.cox.net/ron.l.johnson | | | | Regarding war zones: "There's nothing sacrosanct about a | | hotel with a bunch of journalists in it." | | Marine Lt. Gen. Bernard E. Trainor (Retired) | +-----------------------------------------------------------+
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