Entity-Relationship Diagram

Last updated 4 months ago

Create Entity-Relationship Diagram

To create a Entity-Relationship Diagram:

  1. Select first an element where a new Entity-Relationship Diagram to be contained as a child.

  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. Select an Element where a new Data Model to be contained.

  2. Select Model | Add | Data Model in Menu Bar or Add | Data Model in Context Menu.

Entity

To create an Entity:

  1. Select Entity in Toolbox.

  2. Drag on the diagram as the size of Entity.

To create a Entity (model element only) by Menu:

  1. Select a Data Model where a new Entity to be contained.

  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. Select an Entity.

  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. Select One-to-One Relationship, One-to-Many Relationship or Many-to-Many Relationship in Toolbox.

  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.