Re: changing null-values' sort order
От | Nikolay Samokhvalov |
---|---|
Тема | Re: changing null-values' sort order |
Дата | |
Msg-id | e431ff4c0511200101o392a9fbh@mail.gmail.com обсуждение исходный текст |
Ответ на | changing null-values' sort order (<me@alternize.com>) |
Список | pgsql-novice |
unfortunately, standard 'nulls first/last' isn't supported yet. to change behaviour you should use following statement: select v_date, v_userid from votes order by v_date is not null desc, v_date desc or, something like this: select v_date, v_userid from votes order by coalesce(v_date, XXX) desc where XXX is substituted by the date value that is smaller than any other used in your table On 20/11/05, me@alternize.com <me@alternize.com> wrote: > > hi list > > coming from the MS-SQL Server world, we're migrating our applications slowly > to pgsql 8.1. now we thumbled on a problem with different sort-order > behaviours: > > we got a table with dated records: > table: votes (v_userid, v_date) > > the v_date field can either be null or a date in the past. in mssql, sorting > the table to list records in descending date-order > > select v_date, v_userid from votes order by v_date desc > > produces a list where first the records with dates are listed, and then the > ones with nulls. in pgsql, the null-records are listed first before the > date-records... how can this behaviour be changed? > > mssql: > -------- > 2005-11-05 3 > 2005-11-01 4 > 2005-09-10 1 > null 2 > null 5 > > > pgsql: > -------- > > null 2 > null 52005-11-05 3 > 2005-11-01 4 > 2005-09-10 1 > > thanks in advance, > thomas -- Best regards, Nikolay
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