This page describes Calíope 1.7, the version I am building right now. 1.6 is on the App Store for the Mac, iPad, iPhone, Apple Watch, Apple TV and Apple Vision Pro. The changelog says which version each feature landed in.
Adds an “Open in Calíope” button to every topic. It only works with the app installed.
Visualize the relationships between tables in a database.
Where it is: Workspace › Tools › ER Diagram
Open the ER Diagram from the workspace navigation bar. Select the database in the top selector and Calíope will load the tables with their columns and existing foreign key relationships.
The diagram displays tables as nodes with columns and data types. Lines between tables represent the foreign keys detected on the server.
SQL Server
In SQL Server each schema is its own entry in the selector (demo.dbo, demo.rrhh). To see a foreign key that crosses schemas, add the other one with + DB: the line between the two is drawn in amber, as between two databases.
Keywords: ER, entity relationship, diagram, FK, foreign key, relationships, ERD
Zooming in and out — on macOS, the mouse wheel, a two-finger pinch on the trackpad, or the toolbar buttons; on iPad, the pinch or those same buttons. The percentage between the toolbar's − and + shows the current scale, and the shortcuts are ⌘−, ⌘+ and ⌘0. The limits are the same everywhere: 18 % to 400 %, and the button dims once you reach either end.
Panning the canvas — drag over an empty area, everywhere. Over a node, dragging moves the table instead.
Getting the whole diagram back — the Fit to window button (⌘0) frames every table. The diagram also re-fits itself when it opens and when the window is resized.
The Auto layout button rearranges the nodes to minimize overlaps.
Apple Vision Pro: as on iPad, with its own gestures: pinch and move to pan or to move a table, and pinch with both hands to zoom. The buttons and shortcuts are the same.
Keywords: zoom, pan, scroll, zoom in, zoom out, canvas, navigate
Draw a new foreign key relationship between two tables.
Where it is: ER Diagram › right-click › Create FK relationship
Open the context menu on a table — right-click on macOS, press and hold on iPad — and select New FK relation…. A dialog opens to choose the source table and column, and the target table and column. When confirmed, Calíope executes the ALTER TABLE … ADD FOREIGN KEY on the server.
On macOS only, in addition: hold ⌃ (Control) and drag from one table to the target one; a rubber-band line follows the gesture and releasing opens that same dialog. On iPad the gesture does not exist, and the foreign key is created from the context menu.
Apple Vision Pro: look at the table and pinch and hold, as you would touch and hold it on iPad; Control-drag is Mac only.
Keywords: FK, foreign key, create relationship, ALTER TABLE, referential integrity
Keep the arrangement you gave the diagram, one per database.
Where it is: ER Diagram › Save layout
Click Save layout in the ER Diagram toolbar. Where you dragged each table is stored per database, so every diagram keeps its own arrangement.
The next time you open the diagram for that database, the tables come back where you left them. A table with no saved position — the ones of a second database you have just added with + DB, or one created since — is laid out on a grid beside the rest, never on top of them.
In the ER Diagram toolbar, the Export button offers two formats: PNG (an image, ready to paste into a document or a chat) and PDF (ready for printing or presentation). Each one offers three sizes. On the Mac you choose where to save the file in the system dialog; elsewhere the Share sheet opens, from which you save it to Files or send it.
On the Mac the same formats are also in the canvas context menu, and the diagram can be printed with ⌘P.
Inspect the full structure of a table directly from the diagram.
Where it is: ER Diagram › right-click › Edit table structure
Open the context menu on a table node in the diagram — right-click on macOS, press and hold on iPad — and select Edit table structure. A panel opens showing the complete CREATE TABLE statement for the selected table.
The canvas is a drawing: VoiceOver reads it as a list of tables with their columns, types and keys, and of relationships.
Where it is: Workspace › Tools › ER Diagram
The diagram canvas is a drawing that VoiceOver cannot read, so Calíope offers it as a list. The Tables section has one row per table, with its columns, their types and whether each belongs to the primary key (PK) or to a declared foreign key (FK). If there are relationships, the Relationships section reads each one as «origin → destination», with database, table and column.
It works the same on every platform.
Keywords: VoiceOver, accessibility, ER diagram, tables, relationships
Add a second database to the ER diagram canvas to visualize relationships across databases.
Where it is: ER Diagram › + DB
The ER Diagram can display tables from two databases simultaneously on the same canvas, including foreign keys that cross from one database to the other.
How to add a second database:
1. With the ER Diagram open, select the primary DB in the left selector of the toolbar.
2. Click the + DB button in the toolbar to add a second database.
3. Select the second DB in the new selector that appears.
4. The canvas updates automatically, showing the tables of both databases.
Color coding:
- Blue header — tables from the primary DB.
- Teal header — tables from the second DB.
- Orange arrows — foreign key relationships that cross from one database to the other.
- Regular arrows — relationships within the same database.
Requirement for cross-database relationships:
Foreign keys must be declared on the server: the diagram reads them from the engine's catalog. If cross-database relationships do not appear, verify that the FKs exist formally (not just as naming conventions).
Navigation and export:
All features of the standard ER diagram apply to the multi-database canvas: zoom, pan, auto-layout, save layout, export PNG/PDF, and view table DDL. See the ER Diagram topics for more details.
Available on macOS, iPad, iPhone and Apple Vision Pro.
Keywords: erd, multi-database, cross-database, relationships, second database, foreign key, diagram, multi-db, blue header, teal header, orange arrows