Re: JDBC problem
От | Cedar Cox |
---|---|
Тема | Re: JDBC problem |
Дата | |
Msg-id | Pine.LNX.4.21.0008251145460.14895-100000@nanu.visionforisrael.com обсуждение исходный текст |
Ответ на | Re: JDBC problem (John McKown <jmckown@prodigy.net>) |
Ответы |
Re: JDBC problem
Re: JDBC problem |
Список | pgsql-interfaces |
On Thu, 24 Aug 2000, John McKown wrote: > The syntax that I've seen is: > > insert into KEY_ITEM (key_item_id,keyname) values > (select max(key_item_id)+1,'?' FROM KEY_ITEM); > > Just out of curiousity, why not make key_item_id a SERIAL field? That way, > if you don't specify a value, it gets the next value from the associated > sequence. I was going to ask you to explain SERIAL but the documentation makes it fairly clear.. basically just the next value, yes? Simply setting the field type to SERIAL seems to be the same as the MS Access 'autonumber' field. Is this correct? One detail that seems to have an advantage over the MAX+1 method is that in the case of adding a new record, deleting it, then adding another new record the ID will not be reused (correct?). Question: What happens when transactions enter the picture? Will you get duplicate values, or holes, or does it work just fine? -Cedar
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