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I had to update Visual Studio to get it to work.
When I click on that link, it sends me here:
https://onedrive.live.com/?cid=9E14529A50EA5A6B&id=9E14529A50EA5A6B%21346&parId=root&o=OneUp
The preview doesn't display, but if you click the download button, the Employee.orm file downloads OK, and it opens in my version ...
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Yes, NORMA can map any relational view generated from an ORM schema to SQL. For example, see NORMA Lab1 (accessible from the ORM Foundation website or my www.orm.net website). For more details on the SQL mapping procedure, see Appendix A (pp. 157-164) of Halpin, T. 2015, Object-Role Modeling Fundamentals,
Technics Publications, New ...
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Thanks for your further response, Nicola.
Linking Enrollment to LabSessionNr is correct, as Enrollment already contains the relevant Course. Of course, many lab sessions may have the same number, but this is not a problem.
In modeling, one may often choose between using a derivation rule or subset constraint.
As ...
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Hi Nicola
Please see the attached pdf file for further thoughts on your example and its relational mapping in NORMA. I think this shows a more realistic way to model the example that avoids the mapping issue that you raised.
Cheers
Terry
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Hi Nicola
I get a different relational mapping result when I use NORMA. Please see the attached pdf file for some discussion on this issue.
Cheers
Terry
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To meet your objective in ORM, you could derive a relationship that is the union of the two other relationships, then subset from the given relationship to the derived one. For example, consider the binary relationships with predicates R, S and T from A to B. Now create a derived predicate U from A to B. so that forall x, y [xUy if (xRy v ...
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I assume you mean slide 25 of Lab 4. The square brackets are around role names. NORMA automatically adds the square brackets when you enter the role name. To add a role name, right-click the role box and enter the name in the Name property.
Cheers
Terry
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Hi Gordon
Yes, an irreflexive ring constraint is equivalent to a value-comparison constraint with the inequality operator. E.g. a simple irreflexive constraint on a binary predicate R formalizes as forall x not xRx, and a corresponding value-inequality constraint formalizes as forall x, y (xRy -> ~x=y). It's easy to prove ...
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Hi Jeff
Which file do you mean by "Tutorial 1"?
If you mean NORMA Lab 1 (which I updated on 2016 August 31), then slides 22-24 don't have any verbalization on them. Please clarify.
Cheers
Terry
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ORM recognizes three kinds of object types: entity type (e.g. Country); domain value type (e.g. CountryCode) often shortened to "value type", and data type (e.g. string). Value types carry more semantics than data types (e.g. the CountryCodes 'CH'and 'DE' are based on Latin and German ...