Figure 3-18: Panning and zooming. The novelty of this approach is not merely that constraint contradictions are detected, but mainly that it provides the causes and suggestions to resolve contradictions. In the Format list, click on the format you want to use. Formatting may be used to describe the format in which values are displayed. By default, this installation does not install Visio for Enterprise Architects. The challenges of managing terabytes and exabytes of data and expanding data management to include other data modalities while maintaining the fundamental tenets of database management data independence, data integrity, data consistency, etc are important issues for any organization today. All that remains is to add the foreign key connection between the tables.
The book has four main parts. Follow the instructions in the Install Wizard to complete the installation of Visual Studio. Trying to make this association will only lead to confusion. You should seek product performance information in the relevant product manuals. For example, the residence fact mentioned above might be stored in a resident Country attribute of a Patient table. For Oracle databases, the tool can be configured to create an Oracle Sequence object for all auto counter primary keys.
Be careful not to click on the red and white window exit button because that will instantly close Visio. Use the reports described in Chapter 9 to communicate with nontechnical domain experts. Examples like this are very handy for validating constraints with domain experts. Drag a Predicate shape from the stencil onto the Drawing Window, and click one of its roles twice. By default, the fact editor's input style is Guided, which is easier for occasional users. This enters the unary fact type into the model, and prompts you for a new fact type starting with Patient.
It is very rare for a role played by a value type to be declared mandatory. The fact types pane of the Business Rules window can also be used to locate an instance of the fact type in the diagram. Care is required in designing the relation schemes table structures used to store the facts. With Guided input, you can select the arity from the Guided drop-down list box. If you wish to run Visio on an existing Visio document file, you can do so by double-clicking that. If you are new to database analysis and design, you should follow the natural sequence of the book. To ensure that objects are well-identified, and the facts are all elementary, this may be restated as the following four facts: The The The The Patient Patient Patient Patient with with with with patient patient patient patient number number number number '1025' '1025' '1025' '1025' has the PatientName 'Ann Jones'.
Sex Code , the constraint is understood to apply to the associated value type, e. To toggle the constraint off, press the space bar again. Figure 4-3: If the reference scheme is unit-based, set its type to Measurement. He believes that the purpose of a data model is to turn business requirements into buildable specifications. Choose To select from a set of options, such as radio buttons or check-boxes.
Views are discussed in a later chapter. A useful coverage of database administration procedures and practices may be found in Mullins 2002. This opens the Header and Footer dialog shown in Figure 3-23. If the role is mandatory for the object type, a black dot is added; otherwise the role is optional. Fact-oriented approaches to information modelling facilitate high fidelity models by lifting the specification of business facts and rules to a truly conceptual level where they can be easily validated with non-technical domain experts. The first fact type is included in the selection even though it is not highlighted with the others see Figure 3-30. As far as I know, there is no other book that takes on this subject, and this one does a good job of it.
For example right-click the Country row of the table in Figure 4-1, and select Find Object Type in Drawing from the context menu. You can easily view or hide a toolbar by clicking on its checkbox. You can simultaneously open as many stencils as you like. Double-click the object type to display its Database Properties see Figure 4-6. For the Left, Center, or Right regions of the header or footer, enter any text that you want to include in that region. Identification is the normal case, and is the best choice for Country code.
The rest of the sentence is parsed as the predicate. Each phase occurs within the context of the previous phase. A nonkey attribute is neither a key nor part of a composite key. It does not allow you to specify internal, set-comparison constraints e. Some examples were considered in the previous chapter. Choose the folder where you want to save the model, add a filename for the conceptual schema e. The first time Visio runs, it takes a while to update its directory cache before you can use it.
Numbers are used because in general the same object type may play more than one role in the same predicate. For tidiness, grid lines have been suppressed. Figure 3-36: Adding column details to the Patient table. Figure 3-3: Choosing either the default or a custom installation. This process is normally divided into separate modeling phases.