You can change the attribute name e. g. in the following cases:
- When you create a self-relationship.
- Whenever you want to change a Foreign Key attribute name.
You have just added a self-relationship to the Film entity.
- A copy of your identifying key attribute has been created in the entity - Film ID. Now you have two Film ID attributes in the Film entity.
- Edit the newly created Film ID attribute, define a new Name . The link to parent attribute is displayed on top right-hand corner of the form.
- Confirm OK and see the change on the Workspace.
Advanced Database Design
Toad Data Modeler allows you to design Entity Relationship Diagrams of specific database platforms, convert physical model from one database platform to another, create an ER Diagram directly from your database (Reverse Engineering feature), update physical models, generate DDL/SQL scripts and Change Scripts, create Dictionary Types, Views, Triggers, Functions, generate detailed documentation to your model (in HTML, RTF, PDF, XSLT formats) and much more.
This chapter describes features and functions related to Physical Data Modeling. Look around each section to get the information you need.
Note: See the sample physical model Videorental (Oracle 10g db) that is included in the installation package of Toad Data Modeler. Default location is: C:\Program Files (x86)\Quest Software\Toad Data Modeler7.1\Samples.
Benefits of Physical Data Model
- Detailed definition of database structure, including database specific items, for example:
- Stored procedures
- Materialized views
- Sequences (auto increments) etc.
- Possibility to synchronize local model with existing database.
- Possibility to specify logical names for objects (captions for tables, attributes and other objects).
- Detailed database specific information can be exported to HTML/RTF/PDF or XML/XHTML/CSV reports.
- Automatic generation of SQL code for selected objects (SQL code generation is not available in Logical and Universal Model)
- Automatic migration of PK attributes to child entities (Attributes don't migrate to child entities in Logical Model)
About Advanced Options
Toad Data Modeler supports several database systems. As there are differences among databases, there are only applicable to specific databases.
- Microsoft SQL Server 2000 and higher only support Dictionary Types, which are called User-Defined Data Types in database itself
- PostgreSQL databases do not support Users, only User Groups. Instead of Users, Roles are used for managing permissions.
- and others...
Database platform and version specific information are listed in the respective topics in the Databases chapter.
You can create a relationship between a Parent and Child entities using:
- Key (Primary or Alternate Key) of parent entity
- Unique Index of parent entity
Alternate keys are used when you want to link two entities using two attributes. These two attributes make one unique item.
You would like to create a composite alternate key which contains Title and Director attributes in the Film entity.
- Edit the Film entity.
- In the Entity Properties form click the Keys tab. Here, primary keys and alternate keys are stored, and you can manage them easily using the Add, Edit and Delete buttons. Now click Add to create a new key and confirm by clicking Apply.
- Edit the new key.
- Define its properties on tab General and then switch to the Attributes tab.
- From the window Available, select attributes Title and Director and click the Add arrow button to move them to the Selected window.
- Set properties in other tabs as you wish (e.g. Notes) and confirm.
Scenario: After creating the alternate key, you would like to use it for linking entities.
To select the alternate key for relationship
- Double-click the relationship.
- From the Parent Key box, select the alternate composite key title-director.