Well, I think David has summarized it all.
> ... > But as I wrote: *an SQL AND or OR operator is no AndElse or OrElse > operator because the order of evaluation is not determined by the > operator but by the execution engine. *And I don't know if the engine > really guarantees the execution of both paths with the bitwise | or & > operators shown in your links if both arguments are of bit type. > ... I'd just like to add a bit about your concern. As far as my understanding the way NH works (or at least the way it's supposed to be :D), the semantics of "AndAlso" and "OrElse" are preserved (the order of evaluation is not determined by CLR, but by SQL Server execution engine), in the sense that the generated SQL would have "AND" and "OR" respectively, instead of "&" nor "|". On Mon, Dec 5, 2011 at 6:52 PM, David Schmitt <[email protected]> wrote: > On 05.12.2011 11:51, CSharper wrote: > >> Yes, but they are meant for integral data types where they actually >> make a difference. The documentation link you have in there says it >> works with two bits in 2008 R2 also but I tried with 2008 and it did >> not work with bits there. >> But as I wrote: an SQL AND or OR operator is no AndElse or OrElse >> operator because the order of evaluation is not determined by the >> operator but by the execution engine. And I don't know if the engine >> really guarantees the execution of both paths with the bitwise | or& >> operators shown in your links if both arguments are of bit type. >> >> So for Boolean I would say the right thing to do is support both >> variants of .NET operators all with using the logical operators in >> SQL. >> > > As long as you're using only side-effect-free functions in your boolean > clauses (which is, like, everything in standard SQL), short-circuiting does > not change the outcome of the result and is therefore not relevant to the > discussion. > > The differences between bitwise and boolean operators on the other side > are big, well-defined and mathematically sound. Nothing to discuss here > either. > > The mapping from the boolean/bitwise concepts to And/AndElse in VB is > pretty much written in stone, since Microsoft made that decision and masses > of VB programmers learnt which is which. > > So, if you cannot be convinced of the rightness of using the proper > operator for the operation you want, you are free to change NHibernate's > source to your liking, but do not expect agreement from the rest of the > world, or pity if you get a publication on http://thedailywtf.com/ > > > Best Regards, David > >> >> >> On 5 Dez., 10:19, Maximilian Raditya<[email protected]> wrote: >> >>> On Mon, Dec 5, 2011 at 3:44 PM, >>> CSharper<csharper2...@**googlemail.com<[email protected]> >>> >wrote: >>> >>> Maybe that's the way it's currently working with NHibernate but for >>>> Boolean operands, both operators should work in a query language >>>> targeting SQL in the background. >>>> >>> >>> Doesn't SQL have both operators: logical (http://msdn.microsoft.com/en-* >>> *us/library/ms189773.aspx<http://msdn.microsoft.com/en-us/library/ms189773.aspx>) >>> and bitwise >>> (http://msdn.microsoft.com/en-**us/library/ms176122.aspx<http://msdn.microsoft.com/en-us/library/ms176122.aspx> >>> )? >>> >>> The operator behaviour of SQL is neither exactly like the short >>>> circuit&& (or ||) nor the bitwise Boolean& (or |) operators. SQL >>>> >>>> engines might do lazy evaluation like the short circuit operators but >>>> the order of evaluation is chosen by the query optimizer. In contrast >>>> to the&& operator where the left hand side is guaranteed to be >>>> >>>> evaluated first and the right hand side is only evaluated if required, >>>> the query execution might do it the other way round depending on the >>>> complexity and usable indexes available in the operands. >>>> >>> >>> I don't know how query optimizer works internally, but I do know that >>> they >>> are different and have different semantics. >>> >>> Maybe it would be better to not force the VB programmers to always add >>>> this dumb "Else" word in the queries and allow the Boolean operator of >>>> the C# programmer's choice. >>>> >>> >>> I'm not sure who force to do so, but all I can say is that they have >>> different semantics and need to be differentiated. I presume your concern >>> comes from the confusion of "AND" in SQL is a logical operator, while >>> "AND" >>> in VB is a bitwise one, and it becomes unnatural to you. >>> If you're curious to know why they design it that way, you should >>> probably >>> ask MS team directly :D. >>> >>> -- >>> Regards, >>> >>> Maximilian Haru Raditya >>> >> >> > -- > You received this message because you are subscribed to the Google Groups > "nhusers" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to nhusers+unsubscribe@** > googlegroups.com <nhusers%[email protected]>. > For more options, visit this group at http://groups.google.com/** > group/nhusers?hl=en <http://groups.google.com/group/nhusers?hl=en>. > > -- Regards, Maximilian Haru Raditya -- You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected]. 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