Arthur Fuller
artful at rogers.com
Wed Jun 30 09:57:06 CDT 2004
Good example, and good reasoning, and I agree that dynamic SQL is never out of the question. What I intended to write is that more often than not, dynamic SQL is the lazy way out of thinking carefully about sprocs. Most of the time it is unnecessary and costly in terms of performance and front-end code; some of the time, there is no other way. Arthur -----Original Message----- From: dba-sqlserver-bounces at databaseadvisors.com [mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of Billy Pang Sent: Wednesday, June 30, 2004 12:57 AM To: dba-sqlserver at databaseadvisors.com Subject: RE: [dba-SQLServer] Difference between views and queries oh boy, can't wait to get into this discussion :)...there is one example I can think of.. the example would be based on the physical storage of the sproc in a single db. it is not possible for a sproc to query table in another db that the sproc does not reside in. To illustrate, let's say that there are three copies of the northwind db on db server: northwind0, northwind1 and northwind2; all three have exact db schema; Your goal is to develop a report that counts number of records in the products table in each of the northwind databases. sometimes you may only want to count records in northwind0 and northwind1 but not northwind2; sometimes you may only want northwind2 and northwind1 but not northwind0; and sometimes you want all three northwind dbs in your count. It is possible to create a sp for each of the permutation but if a fourth northwind db is introduced to the system, then the code base is doubled. The alternate solution would be to build dynamic sql to piece together select statement referencing tables using the [db].[owner].[table] format; which tables are pieced together is based on what the user selects as criteria for report. Not elegant solution but it is a lot less code to maintain. With that being said, dynamic sql is not as safe for reporting compared to sproc. I think what Francis is trying to get at is that it is not possible for a developer to claim that a particular "coding method" is never needed. Rather, it is more correct to state that it is not likely that a particular "coding method" is ever needed. Difference between the words "impossible" and "improbable". Similiar to how a judge cannot hand out a verdict to court case before the case is presented no matter obvious it may seem. Another point of reference on this topic would be look up "Validating User Input" in BOL for best practices on this issue. Billy >From: "Arthur Fuller" <artful at rogers.com> >Reply-To: dba-sqlserver at databaseadvisors.com >To: <dba-sqlserver at databaseadvisors.com> >Subject: RE: [dba-SQLServer] Difference between views and queries >Date: Tue, 29 Jun 2004 20:08:54 -0400 > >All I want is an example that cannot be coded by one or more sprocs. > >Arthur > >-----Original Message----- >From: dba-sqlserver-bounces at databaseadvisors.com >[mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of >Francis Harvey >Sent: Tuesday, June 29, 2004 10:47 AM >To: 'dba-sqlserver at databaseadvisors.com' >Subject: RE: [dba-SQLServer] Difference between views and queries > > >Francisco, > >I would like to consider the opinion of someone who shares my namesake >as seriously as possible, but in this case, I believe you suffer from >Arthur's problem of a lack of experience with the very specific >problems I cited. It is fine to talk about not using dynamic SQL in >general when using SQL Server, but just as with normalization, there >are exceptions and no one should be stating it as an absolute rule or >bad practice until they have reviewed the problems I mentioned. Again, >I will state, for those particular problems, dynamic SQL is often the >superior solution. > >Also, the "scaling" issue is teetering awfully close to using FUD. You >can always use any programming method incorrectly, but correctly >written dynamic SQL does not suffer from the horrible efficiency loss >that not having a cached query plan would seem to imply. Similarly, the >"time spent" argument is bad logic. I don't spend less time on my >dynamic SQL solutions, I spend more time because the problems are >difficult. Adding more time for a static SQL solution will not result >in a better design or even a working design in some cases. > >I don't think you, Arthur or I are in disagreement over security, I >just didn't like the oversimplified way security was described, so I >chose to emphasize a particular point. I think this is an important >part that should be highlighted. > >Francis R Harvey III >WB 303, (301)294-3952 >harveyf1 at westat.com > > > > -----Original Message----- > > From: dba-sqlserver-bounces at databaseadvisors.com > > [mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of > > Francisco H Tapia > > Sent: Monday, June 28, 2004 12:42 PM > > To: dba-sqlserver at databaseadvisors.com > > Subject: Re: [dba-SQLServer] Difference between views and queries > > > > > > Francis, > > I respectfully agree w/ Arthur on this. Dynamic SQL as a rule, > > is bad design. Many times over you will find that there are > > comparable solutions that often meet the demand much better, and > > "scale" much better than that of dynamic sql. There is no "ONE" > > right way of doing things, that is the nature of this business. > > However justifying dynamic > > sql because of some time spent on design is imnsho incorrect. > > You will > > often find more times that enabling users/roles via Views/Sprocs and > > Functions to be far superior solutions than to open wide dynamic sql. > > > > re: security. > > Of course if you deny permissions on any object the take precedence > > over allows, this is the nature of security. That is why you must > > be explicitly "SURE" when making DENY requests on any object. > > NOT giving > > rights to an object does not equeal REJECT. > > > > If I do not give a user rights to a view, under Role1, but then give > > him rights to that object via Role2. There will be 0 issues w/ > > accessability. However If by poor planning I had a "REJECT" > > rights in > > Role1, then I'd have the issues you are stating. > > > > > > > > > > Francis Harvey wrote On 6/25/2004 2:24 PM: > > > > >Arthur, > > > > > >Do some research on the basic solutions for SQL that has to > > adjust for > > >varying databases, conditions (dynamic search), or servers > > >(different > > > >SQL dialects). Some designs also call for encapsulating > > business logic > > >outside of the data tier. In these situations, dynamic SQL is often > > >the only logical choice. I have only had to deal with dynamic > > >search myself, but this is enough to convince me of its usefulness. > > > > > >Describing permissions solely as additive in nature is > > incorrect. This > > >is the point I was making. > > > > > >Francis R Harvey III > > >WB 303, (301)294-3952 > > >harveyf1 at westat.com ><snip> >_______________________________________________ >dba-SQLServer mailing list >dba-SQLServer at databaseadvisors.com >http://databaseadvisors.com/mailman/listinfo/dba-sqlserver >http://www.databaseadvisors.com > >_______________________________________________ >dba-SQLServer mailing list >dba-SQLServer at databaseadvisors.com >http://databaseadvisors.com/mailman/listinfo/dba-sqlserver >http://www.databaseadvisors.com > _________________________________________________________________ MSN Premium with Virus Guard and Firewall* from McAfeeR Security : 2 months FREE* http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU =http://hotmail.com/enca&HL=Market_MSNIS_Taglines _______________________________________________ dba-SQLServer mailing list dba-SQLServer at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/dba-sqlserver http://www.databaseadvisors.com