Relationships (foreign keys)
A relationship is a foreign key linking one field to another. EntityFlow draws them as orthogonal edges and keeps them attached as you move tables around.
Creating a relationship
Hover over a field until a circular port appears on the edge of the card, then drag from that port onto a target field's port — the edge snaps to the nearest one. EntityFlow routes the edge orthogonally and shows cardinality badges at both ends.
Reconnecting & deleting
- Reconnect: select the edge and drag a grab handle to a new port.
- Auto-route an end: double-click a handle to clear its anchor and return that end to automatic routing.
- Delete: select the edge and press
Delete/Backspace, or use the trash icon in the Refs panel.
Cardinality
Edit cardinality in the Refs panel with the per-end buttons. The symbols are:
| Symbol | Meaning |
|---|---|
0 | Optional |
1 | One |
+ / * | Many |
Toggle every cardinality badge at once via View → Show / Hide cardinalities.
Manual routing
Select an edge to reveal bend handles on its vertical lane. Drag horizontally to bend the edge into the shape you want. Double-click a segment to reset that edge to automatic routing.
:::note Self-loops A field linked to another field on the same table draws as a curved self-loop. :::
Styling an edge
Style each edge in the Refs panel:
- Line colour — 8 swatches plus a custom colour
- Width — S (
1.5px), M (2.5px), or L (3.5px) - Solid or Dashed
In the Acme Storefront sample, the FK order_items.product_id → products crosses from the Sales & Fulfilment group into Catalog — a good edge to colour and thicken so the cross-group link stands out.