Re: select first occurrence of a table
От | Dennis Gearon |
---|---|
Тема | Re: select first occurrence of a table |
Дата | |
Msg-id | 3EB2B1BF.8040407@cvc.net обсуждение исходный текст |
Ответ на | select first occurrence of a table ("Johnson, Shaunn" <SJohnson6@bcbsm.com>) |
Список | pgsql-general |
That's why they have something called 'surrogate keys', usually a sequence column. google for that term. I wouldn't be toohard to write a function in PL/PGSQL to fill an added key column. Johnson, Shaunn wrote: > Have a general SQL question: > > I have a table that happens to have a some > duplicate entries in it (entire rows). I would like > to update one row and change one thing > about it, but it seems that I need a unique value > to do it; otherwise, I wind up changing multiple > rows. > > For example: I have a table that looks like this > > [snip table] > > Table "survey_processed_dt" > Column | Type | Modifiers > -------------------+---------------------------+----------- > survid | character(8) | > processed_id | character varying(2) | > processed_dt | date | > > [/snip table] > > And the rows look like this: > > > [snip rows] > > bcn=> select * from survey_processed_dt where survid = '02021000' and > processed_id = '05'; > survid | processed_id | processed_dt > ----------+--------------+-------------- > 02021000 | 05 | 2003-01-16 > 02021000 | 05 | 2003-01-16 > (2 rows) > > [/snip rows] > > I want to change ONE of the rows ... is there a way to > just select the first occurrence of a row to update? > > Suggestions? > > Thanks! > > -X >
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