Re: difference between join syntax
От | Tom Lane |
---|---|
Тема | Re: difference between join syntax |
Дата | |
Msg-id | 18155.1093827260@sss.pgh.pa.us обсуждение исходный текст |
Ответ на | difference between join syntax (Natan <nvivo@mandic.com.br>) |
Список | pgsql-novice |
Natan <nvivo@mandic.com.br> writes: > Can anyone tell me if there is any difference between these two commands: > select * from table1, table2 where table1.id = table2.id > and > select * from table1 inner join table 2 on table1.id = table2.id Nope. > I checked the query plan for both and they appear exactly the same. But > in this case, i am working with only two tables in a very simple > join.... What i would like to know is: in a production environment with > lots of joins and where clauses, does it make any difference to write in > one form or in the other, or the joins are like shortcuts to the first form? With more than two tables, it *can* make a difference. If using 7.4, see http://www.postgresql.org/docs/7.4/static/explicit-joins.html Earlier versions were a bit different --- make the obvious change in the URL to see the corresponding docs for your version. regards, tom lane
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