Re: Demo: Modelling Cost of Travel Paths Between Towns

"Neo" <neo55592_at_hotmail.com> wrote in message news:4b45d3ad.0411151332.4acd7159_at_posting.google.com...
> > > user can easily create code that will update the age of any thing
> > > whose name is john and has an age, including that of things whose
> > > class is unknow at design-time (ie a person, dog, cat, pig, plane, etc
> > > in the future). Try coding that in RM.
> >
> > It doesn't get a whole lot easier:
> > UPDATE your_table
> > SET age = age + 1
> > WHERE name = 'john'
> > AND age IS NOT NULL;
>
> 09:00 - You write the above query and store it as a procedure.
> 10:00 - I create a table named T_Rats and insert john whose age is 2.
> 11:00 - I run your procedure that you created at 9:00.
>
> Your query fails because "your_table" doesn't exist.
>
> The following XDb2 query written at 09:00 finds the rat at 11:00.
> SELECT2 %.age & %.name=john;

When did table (your_table) vanish? It didn't. And what does your creating a new table have to do with it? Absolutely nothing. I really think you have no clue at all. Received on Tue Nov 16 2004 - 15:15:55 CET