Re: Demo: Modelling Cost of Travel Paths Between Towns

> > 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; Received on Mon Nov 15 2004 - 22:32:17 CET