To Add Degree and Class to a Relationship

Once you have a Relation joined to two or more Entities by Lines you can associatate the degree and class of the relationship in the form of a cardinality string.

The following are examples of valid degree and class notations that should be associates with the appropriate end of the relationship.

1

meaning one and only one
(i.e. Each {ent} must {rel} one and only one {ent} or
Each {ent} {rel} one and only one {ent}).,

0 <= m

meaning none or many
(i.e. Each {ent} may {rel} one or more {ent} or
Each {ent} {rel} none, one or more {ent}).,

1 <= m

meaning one or many
(i.e. Each {ent} must {rel} one or more {ent} or
Each {ent} {rel} one or more {ent}).,

0 <= n <= 1

meaning a value of 'n' between 0 and 1
(i.e. Each {ent} may {rel} one {ent} or
Each {ent} {rel} none or one {ent}).,

*<Comment>*

Comments are delimited by asterisks, comments can be used in addition to other notations

This is an abbreviated list showing the more common degree and class notations. For a full syntax description of valid cardinality (combined degree and class) strings refer to the Teamwork manual.

The easiest way to add a cardinality string to a line you should create the cardinality string in 'free space' on the canvas. Then use the MMB "Move Text Block" option to drop the cardinality string on the line using the LMB.

Example

We will use the notation [...] to indicate an Entity and <...> to indicate a relaton.

For the relationship:

• "Each Department may employ many Engineers"
  ("Each Engineer must be assigned to one and only one Department")

We would augment the teamwork diagram to show:

• [Department]--1--<employ>--0<=M--[Engineer]

i.e. Department employs between 0 and many Engineers, Engineer works for one and only one Department.

Remember the cardinality string is only associated with a line when it goes bold.

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