Entity-Relationship Diagram

Entity-Relationship Diagram

Create Entity-Relationship Diagram

To create a Entity-Relationship Diagram:
  1. 1.
    Select first an element where a new Entity-Relationship Diagram to be contained as a child.
  2. 2.
    Select Model | Add Diagram | ER Diagram in Menu Bar or select Add Diagram | ER Diagram in Context Menu.

Data Model

To create a Data Model (model element only) by Menu:
  1. 1.
    Select an Element where a new Data Model to be contained.
  2. 2.
    Select Model | Add | Data Model in Menu Bar or Add | Data Model in Context Menu.

Entity

To create an Entity:
  1. 1.
    Select Entity in Toolbox.
  2. 2.
    Drag on the diagram as the size of Entity.
To create a Entity (model element only) by Menu:
  1. 1.
    Select a Data Model where a new Entity to be contained.
  2. 2.
    Select Model | Add | Entity in Menu Bar or Add | Entity in Context Menu.
You can use QuickEdit for Entity by double-click or press Enter on a selected Entity.
  • Name : Enter name.
  • Add Note : Add a linked note.
  • Add Column (Ctrl+Enter) : Add a column.
  • Add One to One : Add an one-to-one relationship with an entity.
  • Add One to Many : Add an one-to-many relationship with an entity.
  • Add Many to Many : Add an many-to-many relationship with an entity.
To suppress Columns, see Suppress Columns.

Column

To add a Column:
  1. 1.
    Select an Entity.
  2. 2.
    Select Model | Add | Column in Menu Bar or Add | Column in Context Menu.
You can use QuickEdit for Column by double-click or press Enter on a selected Column.
  • Column Expression : Edit column expression.
    Syntax of Column Expression
    column ::= name [ ':' type ] [ '(' length ')' ]
    name ::= (identifier)
    type ::= (identifier)
    length ::= (string)
  • Primary Key : Check whether the column is primary key or not.
  • Add (Ctrl+Enter) : Add one more column in the below.
  • Delete (Ctrl+Delete) : Delete the column
  • Move Up (Ctrl+Up) : Move the column up.
  • Move Down (Ctrl+Down) : Move the column down.

Relationship

To create a Relationship:
  1. 1.
    Select One-to-One Relationship, One-to-Many Relationship or Many-to-Many Relationship in Toolbox.
  2. 2.
    Drag from an entity and drop on another entity.
You can use QuickEdit for Relationship by double-click or press Enter on a selected Relationship.
  • Name : Enter name.
  • Identifying : Check whether the relationship is identifying or not.
  • Add Note : Add a linked note.
You can also use QuickEdit for Relationship End by double-click at the end side of a Relationship.
  • Name : Enter name.
  • Cardinality : Select cardinality of the selected relationship end.