Formulas

A formula computes a read-only field value on write, and the result is stored. Formulas work on six scalar types: string, text, number, currency, integer, and boolean.

{ "name": "total",  "type": "currency", "formula": "quantity * unit_price" },
{ "name": "label",  "type": "string",   "formula": "doc_no & \" / \" & title" },
{ "name": "is_big", "type": "boolean",  "formula": "total > 1000" }

Operators

• Arithmetic: + - * / (and parentheses)
• Comparison: = != < <= > >=
• Logic: AND OR NOT
• String concat: &

Functions

IF(cond, a, b), ROUND(x), NOW(), CONCAT(...).

Aggregations over detail rows

{ "name": "lines_total", "type": "currency", "formula": "SUM(lines.amount)" }

COUNT and SUM work over a details child. AVG skips null values.

Cross-object references

One level deep, referencing a scalar on a relation target:

{ "name": "supplier_label", "type": "string", "formula": "supplier_id.name" }

Null semantics

Rules

• A formula field is read-only: no required, unique, default, primary, or constraints.
• References must resolve to scalar fields (no relations, and no aggregates of aggregates beyond one level).
• Cycles — including cross-object — are rejected at schema build time.
• When a dependency changes, the field is recomputed and persisted on the next write.