Re: most idiomatic way to "update or insert"?
От | Richard Huxton |
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Тема | Re: most idiomatic way to "update or insert"? |
Дата | |
Msg-id | 41127076.3030505@archonet.com обсуждение исходный текст |
Ответ на | Re: most idiomatic way to "update or insert"? (Ron St-Pierre <rstpierre@syscor.com>) |
Ответы |
Re: most idiomatic way to "update or insert"?
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Список | pgsql-general |
Ron St-Pierre wrote: > Richard Huxton wrote: > >> >> An "update or insert" would be useful sometimes, but it's not always >> necessary. Indeed, if I find I don't know whether I'm adding or >> updating something I take a long hard look at my design - it ususally >> means I've not thought clearly about something. > >> Can you give an actual example of where you need this? > > How about stocks for a simple example? Let's say you have a simple table > with the stock symbol, stock exchange, high, low, open, close and > volume. Every day you update the data for each stock. But there are > always new stocks listed on an exchange, so when a new stock shows up > you have to do an insert instead of an update. If it is just a simple table then delete all of them and insert from scratch. If you wanted to track changes over time (perhaps more likely), you'd have a separate table with the company name/address etc and a log table. At which point you'll want to know if it's a new company or not... -- Richard Huxton Archonet Ltd
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