Re: Add Missing From?
От | Bruce Momjian |
---|---|
Тема | Re: Add Missing From? |
Дата | |
Msg-id | 200408101431.i7AEVj410526@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: Add Missing From? (Tom Lane <tgl@sss.pgh.pa.us>) |
Список | pgsql-hackers |
I have added the USING mention to the TODO list description for the item. * Allow DELETE to handle table aliases for self-joins [delete] There is no way to specify a table alias for the deleted table in the DELETE WHERE clause because there is no FROM clause.The agreed approach is to allow a USING clause to specify additional tables with aliases. UPDATE already has suchan optional FROM clause. --------------------------------------------------------------------------- =Tom Lane wrote: > Jan Wieck <JanWieck@Yahoo.com> writes: > > What about > > DELETE FROM staff JOIN users ... > > then? > > I don't much care for that, mainly because in my mind "x JOIN y" should > always be semantically equivalent to "y JOIN x". I think we want a real > clear syntactical separation between the deletion target table and the > other tables. > > Also we do have the precedent of the way that UPDATE does things. We > don't want to use the keyword FROM because of confusion, but I think > we want to keep it basically the same as UPDATE. > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faqs/FAQ.html > -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001+ If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania19073
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