Relations & Lookups

Why link tables?

In Formula, rows are Data objects — they exist independently from tables. A single Data object (like "Acme Corp" or "Project Alpha") can appear in multiple tables, and each table shows different properties of that object.

Relations let you bring information from one table into another, so you can see related data side by side without duplicating it. When the source data changes, all lookup columns reflecting that data update automatically.

The power of linked tables

Creating a lookup column

Add a new column and choose Reference → Lookup. A configuration dialog opens with three modes:

→ From Rows — For each row, look up a cell value from another table where that same row is a member.

→ From Reference Column — Look up a property from the header Data of an existing Reference column.

→ From Data Column — Each row references a different Data object; look up a property from that referenced object.

Select the target table and the column you want to display, then confirm. Lookup columns are always read-only — they show computed values from the source, and refresh automatically when the source data changes.

Adding a Lookup column step by step

Choosing what to display

When configuring a lookup, you choose the source (which table, reference column, or data column) and the specific column to display. The dialog shows all available tables and columns with an inline search.

If the target stores internal IDs, Formula automatically resolves them to human-readable names. All lookup values display with a visual indicator so you can tell them apart from regular columns.

Using lookups in formulas

Lookup columns can be referenced in formulas just like any other column. A lookup column that pulls in a billing rate can be multiplied by hours to calculate a total — and everything stays in sync.

In aggregation functions (SUM, AVERAGE, etc.), the evaluator resolves the lookup value for each row individually, then aggregates the results. Footer formulas like =SUM(["Total From Other Table"]) work correctly.

Real-world example

A small business tracks Clients and Invoices in two tables. The Clients table has Name, Contact Email, and Payment Terms. The Invoices table links to Clients via a Reference column.

Two Lookup columns pull in the Client Email and Payment Terms automatically. When Acme Corp changes their payment terms to "Net 45", every invoice linked to Acme Corp updates instantly — no manual editing needed.