Model Canvas

The following sections detail how to Add, Edit, and Remove Node Labels.

The following sections detail how to Add, Edit, and Remove Relationship Types.

Node Label properties are used to define which key/value property pairs can be assigned to nodes with a specific Node Label. For instance, for a Node Label 'Movie', we might want to include the properties: title, release date, and rating. When entering Node Label Properties in Cypher Workbench, you can specify the following:

The specifics of Adding, Editing, and Deleting are discussed below.

Relationship Type properties are used to define which key/value property pairs can be assigned to relationships with a specific Relationship Type. For instance, for a Relationship Type 'ACTED_IN', we might want to include the property: role. When entering Relationship Type Properties in Cypher Workbench, you can specify the following:

The specifics of Adding, Editing, and Deleting are discussed below.

In the Property Dialog, there is a Show Descriptions button at bottom. Clicking this button will show description fields for the Node Label or Relationship Type at the top, and a Description field under each property. Click Hide Descriptions to hide the Description fields.

Information entered into the Description fields will be shown in the Export HTML and Export Markdown data dictionaries.

In the Property Dialog, there is a Composite Indexes tab. Click on this tab to access the Composite Indexes area. There are two sections in this tab, a section to add a new composite index and the Composite indexes section - a section to view/delete existing composite indexes. At this time, existing composite indexes can not be edited, they must be removed and re-added.

To add a composite index, follow these steps:

The new index will appear in the Composite indexes section. The Compsite indexes section will also show any previously added indexes.

To remove a composite index, click the Trash icon to the right of the index.

In the Neo4j database, a Node Label is a Node Label, there are no primary or secondary node labels. However, in Cypher Workbench, we have made a distinction to assist with data modeling. The Primary Node Label is the Node Label which appears as the text value inside of a circle on the canvas. Secondary Node Labels can be added which appear in an annotation bubble outside of the circle.

Secondary Node Labels can be useful for modeling class/subclass hierarchies if you intend to assign a node instance Node Labels corresponding to both the class and subclass. For instance, we might have a primary Node Label 'Horse', and a secondary Node Label, 'Mammal'. From a modeling perspective, this would indicate that all Horses are Mammals. When data is added to the database, a specific instance, such a horse named Seabiscuit, would have both labels assigned to the node, e.g. (horse1:Horse:Mammal {name: 'Seabiscuit'}).

Secondary Node Labels can also be useful for using Node Labels like tags. For instance you may have a primary Node Label called 'Transaction' and a secondary Node Label called 'Fraud'. For instances of these Node Labels, we could have a non-fraudulent transaction and a fraudulent transaction like this: (txn1:Transaction {id: 1, amt: 5.00}), (txn2:Transaction:Fraud {id: 2, amt: 50000.00}).

To add Secondary Node Labels, click on a Node Label to bring up the arc icons that surround the Node Label. Click on the icon in the upper-left with the 3-bars to show the property dialog. Near the top you will see an editable drop down 'Add Node Label'. Enter a new value or re-use an existing value to assign a Secondary Node Label to the Primary Node Label. You can hover over a Secondary Node Label to edit or delete it.

If you wish for the Secondary Node Label to have color, you must first add it to the canvas as it’s own Primary Node Label, then color it. Once colored, if the Node Label if used a Secondary Node Label elsewhere all instances will take on the color you chose. Afterwards, you can remove the Primary Node Label you just colored if desired.

Relationship Cardinality specifies validation criteria for relationships between 2 node instances. Cardinality is simply counting the number of relationships between 2 nodes. This currently is not enforced in the database, but could potentially be used by data loading tools to ensure the cardinality restrictions are enforced when data is loaded.

To edit Relationship Cardinality, click on a Relationship Type to bring up the icon ribbon. Click on the second from the left icon that looks like a mini-graph to show the Relationship Cardinality dialog.

You can specify both outbound and inbound cardinality:

Both Outbound and Inbound have the following settings: * At least: can specify either 0 (for optional) or 1 * At most: can specify either 1 (for maximum) or many

The defaults are 0 and many.

As an example, let’s say you had a rigid taxonomy where a single :Movie can belong to only one :Genre, but it must belong to at least 1 :Genre. Therefore, our outbound cardinality would be :Movie -HAS_GENRE (1..1)→ :Genre, which indicates that a Movie must have a relationship to a Genre, but it can only have a relationship to a single Genre.

However, we know that many different Movies can belong to the same Genre, or for a new Genre no Movie may belong, so from the inbound perspective of a Genre instance, it would look like :Movie -(0..many) HAS_GENRE→ :Genre.

You can select one or more Node Labels or Relationship Types on the canvas. When multiple items are selected, coloring, sizing, moving, position locking, and deleting will affect all selected items.

You can select an item by single clicking on it, and you can deselect an item by clicking on a blank area of the canvas.

To select multiple items, you can:

If multiple items are selected, you can also hold Command/Ctrl to deselect items.

You can pan the canvas by dragging on a blank area of the canvas. You can zoom the canvas by clicking on the - and + magnifying glass icons in the bottom right of the canvas.

To reset the pan/zoom, click on the cross-hairs icon to the right of the zoom icons.

To search for and highlight a specific item in the canvas, use the magnifying glass icon in the upper-right of the canvas. Clicking the icon will show a drop-down of all items in the canvas. Type in the search box to filter the list. Clicking on an item in the list will select the item and center in the canvas.