Re: SQL problem?
От | Bruno Wolff III |
---|---|
Тема | Re: SQL problem? |
Дата | |
Msg-id | 20050826150931.GA16546@wolff.to обсуждение исходный текст |
Ответ на | Re: SQL problem? ("Charley L. Tiggs" <ctiggs@xpressdocs.com>) |
Список | pgsql-novice |
Please don't top post, it makes it harder to preserve context when replying to your comments. On Fri, Aug 26, 2005 at 09:51:49 -0500, "Charley L. Tiggs" <ctiggs@xpressdocs.com> wrote: > What kind of maintenance problems, if you don't mind my asking? Because if you change your table definition, applications that use '*' in queries will get back different data than they did previously. If you use explicit column lists, only if the listed columns are affected by a change will applications get back different data. '*' is OK to use to save some typing when entering queries by hand, but you shouldn't be using in scripts or applications except in very rare cases. > > Charley > > On Aug 25, 2005, at 9:21 PM, Bruno Wolff III wrote: > > >On Thu, Aug 25, 2005 at 16:47:54 -0700, > > operationsengineer1@yahoo.com wrote: > > > >>>Column names are case-sensitive. > >>>Btw.: SELECT * is evil... > >>> > >>> > >>> > >>>Regards, Andreas. > >>> > >> > >>Andreas, what would you recommend instead of SELECT * > >>if you really do wanty all the results? > >> > > > >Explicitly listing the columns. Using '*' causes maintainance > >problems. While the context should make this obvious, the first period about shouldn't have been there. > > > >---------------------------(end of > >broadcast)--------------------------- > >TIP 6: explain analyze is your friend > > > > > ---------------------------(end of broadcast)--------------------------- > TIP 9: In versions below 8.0, the planner will ignore your desire to > choose an index scan if your joining column's datatypes do not > match
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