Logical Modeling › Entities

Entities

In the logical model, entities represent the tables in a database. The following types of entities are supported:

• Independent entity
• Dependent entity

An entity box has a horizontal line that divides the box. You can enter the primary key above the line and non-keys below the line. You can choose to migrate keys to either the primary or non-key area of the box.

When you add an entity, the entity type is determined based on the relationship it is involved in. For example, when you initially place an entity in a model, it is represented as an independent entity. When you connect the entity to another entity using a relationship, the relationship type is used to determine if the entity is independent or dependent. If an entity is a child entity in an identifying relationship, it appears on the diagram window as a dependent entity. All other entities appear as independent entities.

Note: A dependent entity appears as an entity box with round corners, and an independent entity appears as an entity box with square corners.

You can add an independent and dependent entity using any of the following methods:

• Click in the main Toolbox, and click the diagram window.
• Add a table in the physical model, and open the logical model.
• Reverse engineer an existing database.
• Copy an entity from one model and paste it into another model.
• Right-click the Entities folder in the Model Explorer and choose New.

Note: You can add consecutive multiple entities by pressing the Ctrl key before you click the entity tool. When you click again in the diagram window, another entity is created.

More information:

Add an Entity

Enter an Entity Definition

Enter an Entity User Note

Enter Entity User-Defined Property Values

Attach Icons to an Entity

Specify Volumetric Information for an Entity