@@ -0,0 +1,13 @@
+---
+"@objectstack/service-analytics": patch
+---
+
+The draft-data preview **refuses** a field constraint with zero operators (`{ name: {} }`) instead of answering it with every row, so a drafted chart no longer shows rows for a filter publish refuses outright (#19835).
+
+`preview-evaluator.ts`'s `matchesWhere` iterated a field constraint's entries; an empty object has none, so the loop never ran and the row fell through to a MATCH. `matchesWhere({ name: 'Globex' }, { name: {} })` answered `true`. Every data driver refuses this shape (`driver-memory`, `driver-mongodb`, and `driver-sql` at the top level and inside `$and`/`$or`/`$not`), and so does this package's own `where` door, so the preview and publish gave opposite answers to the same filter.
+
+- **Refused in the ADR-0112 `INVALID_FILTER` / 400 envelope**, through the same `invalidFilterError` the preview already uses for an operator it cannot evaluate. No new error code and no new exported symbol. The message follows the drivers' wording: it names the constraint and its position (`where.$or[1].amount`), and gives the two legal repairs (name an operator, or write a direct comparand).
+- **Not answered as "matches zero rows" either.** `{ status: {} }` does not mean "no rows". Read literally it means "rows whose status is anything", and the shape is almost always an authoring accident: a filter builder that recorded a field but never its operator. Only a refusal names the constraint to repair.
+- **Nesting cannot route around it.** The check walks the whole `where` before any row is read, `$and` / `$or` / `$not` arms included. So a constraint in an `$or` arm that a matching row would short-circuit past still refuses, and so does a seed draft holding zero rows.
+- ⚠️ **What it costs**: a drafted chart whose filter carries `{ field: {} }` now returns `400 INVALID_FILTER` in preview, where before it rendered a number computed over every row. Fix: name the operator the constraint was meant to carry, e.g. `{ status: { $eq: 'open' } }` or `{ status: 'open' }`.
+- **Unchanged**: constraints that name an operator, implicit-equality comparands, and an empty *node* (`where: {}` or `$and: [{}]`, which is the identity and not a field constraint).
@@ -0,0 +1,142 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * [#19835] The draft-preview matcher answered a field constraint with ZERO
+ * operators — `{ name: {} }` — with EVERY row.
+ *
+ * `matchesWhere`'s per-field loop iterates the constraint's entries; an empty
+ * object has none, so the loop never ran and the row fell through to the
+ * closing `return true`. Probe at `origin/main` before the repair:
+ * `matchesWhere({ name: 'Globex' }, { name: {} })` → `true`. The #19810
+ * operator-vocabulary refusal could not reach it: no key, no lookup to fail.
+ *
+ * Every shipped driver refuses the shape (`driver-memory` / `driver-mongodb`
+ * `emptyFieldConstraintError`, `driver-sql` at the top level and inside
+ * combinators) — ruled on #5240, refused everywhere. So the preview charted
+ * every row for a filter publish refuses outright.
+ *
+ * ## What this file pins
+ *
+ * 1. **Refused** — `INVALID_FILTER` / 400 (ADR-0112), pinned by `code` +
+ *    `status`, never by a bare `toThrow()`. ⛔ Not "matches zero rows": that
+ *    is the other silent reading the ruling declined.
+ * 2. **Not bypassable by nesting** — under `$and`, `$or` (including the arm a
+ *    short-circuit would never reach) and `$not`, and over an EMPTY seed.
+ * 3. **Unchanged** — a constraint that names an operator, an implicit
+ *    comparand, and an empty NODE (`{}` as the whole `where` or as a
+ *    combinator arm — the identity, not a field constraint) answer exactly
+ *    what they answered before.
+ */
+
+import { describe, it, expect } from 'vitest';
+import { DatasetSchema } from '@objectstack/spec/ui';
+import type { Cube } from '@objectstack/spec/data';
+import { AnalyticsService } from '../analytics-service.js';
+import { evaluateAnalyticsQueryOverRows, matchesWhere } from '../preview-evaluator.js';
+
+type Refusal = Error & { code?: string; status?: number };
+
+const ROWS: Record<string, unknown>[] = [
+  { id: '1', name: 'Acme Corp', amount: 1200 },
+  { id: '2', name: 'Globex', amount: 800 },
+];
+
+const CUBE: Cube = new AnalyticsService().registerDataset(
+  DatasetSchema.parse({
+    name: 'expense_ds',
+    label: 'Expense',
+    object: 'expense',
+    dimensions: [{ name: 'name', field: 'name', type: 'string', label: 'Name' }],
+    measures: [{ name: 'count', aggregate: 'count' }],
+  }),
+).cube;
+
+function run(where: Record<string, unknown>, rows = ROWS) {
+  return evaluateAnalyticsQueryOverRows(
+    { cube: 'expense_ds', measures: ['count'], dimensions: ['name'], where },
+    CUBE,
+    rows,
+  );
+}
+
+function refusalFor(thunk: () => unknown): Refusal | undefined {
+  try {
+    thunk();
+    return undefined;
+  } catch (e) {
+    return e as Refusal;
+  }
+}
+
+function namesAnswered(where: Record<string, unknown>): string[] {
+  return run(where).rows.map((r) => String(r.name)).sort();
+}
+
+describe('[#19835] a field constraint with zero operators on the draft preview', () => {
+  it('the card probe — `matchesWhere({ name: "Globex" }, { name: {} })` — refuses instead of matching', () => {
+    const err = refusalFor(() => matchesWhere({ name: 'Globex' }, { name: {} }));
+    expect(err).toBeInstanceOf(Error);
+    expect(err).toMatchObject({ code: 'INVALID_FILTER', status: 400 });
+  });
+
+  it('refuses a whole preview query at the top level, naming the field and its position', () => {
+    const err = refusalFor(() => run({ name: {} }));
+    expect(err).toMatchObject({ code: 'INVALID_FILTER', status: 400 });
+    expect(err?.message).toContain('where.name');
+    expect(err?.message).toContain('{ "name": {} }');
+  });
+
+  it('refuses over an EMPTY seed draft — the walk is not a function of the data', () => {
+    expect(refusalFor(() => run({ name: {} }, []))).toMatchObject({ code: 'INVALID_FILTER', status: 400 });
+  });
+
+  describe('nesting cannot route around it', () => {
+    it('inside `$and`', () => {
+      const err = refusalFor(() => run({ $and: [{ name: 'Globex' }, { amount: {} }] }));
+      expect(err).toMatchObject({ code: 'INVALID_FILTER', status: 400 });
+      expect(err?.message).toContain('where.$and[1].amount');
+    });
+
+    it('inside `$or`, in the arm a short-circuit would never reach for a matching row', () => {
+      // Row `Globex` satisfies arm 0, so a per-row walk would `some()` past arm
+      // 1 and answer it; the refusal must not depend on which row is tested.
+      const err = refusalFor(() => run({ $or: [{ name: 'Globex' }, { amount: {} }] }));
+      expect(err).toMatchObject({ code: 'INVALID_FILTER', status: 400 });
+      expect(err?.message).toContain('where.$or[1].amount');
+    });
+
+    it('under `$not`', () => {
+      const err = refusalFor(() => run({ $not: { name: {} } }));
+      expect(err).toMatchObject({ code: 'INVALID_FILTER', status: 400 });
+      expect(err?.message).toContain('where.$not.name');
+    });
+
+    it('several combinators deep', () => {
+      const err = refusalFor(() => run({ $and: [{ $or: [{ $not: { name: {} } }] }] }));
+      expect(err).toMatchObject({ code: 'INVALID_FILTER', status: 400 });
+    });
+
+    it('through `matchesWhere` directly, under `$and`', () => {
+      const err = refusalFor(() => matchesWhere({ name: 'Globex' }, { $and: [{ name: {} }] }));
+      expect(err).toMatchObject({ code: 'INVALID_FILTER', status: 400 });
+    });
+  });
+
+  describe('non-empty constraints answer exactly as before', () => {
+    it('an operator constraint', () => {
+      expect(namesAnswered({ name: { $eq: 'Globex' } })).toEqual(['Globex']);
+      expect(namesAnswered({ amount: { $gt: 1000 } })).toEqual(['Acme Corp']);
+      expect(matchesWhere({ name: 'Globex' }, { name: { $ne: 'Globex' } })).toBe(false);
+    });
+
+    it('an implicit-equality comparand', () => {
+      expect(namesAnswered({ name: 'Globex' })).toEqual(['Globex']);
+    });
+
+    it('an empty NODE — the whole `where`, or a combinator arm — is the identity, not a field constraint', () => {
+      expect(namesAnswered({})).toEqual(['Acme Corp', 'Globex']);
+      expect(namesAnswered({ $and: [{}] })).toEqual(['Acme Corp', 'Globex']);
+      expect(matchesWhere({ name: 'Globex' }, {})).toBe(true);
+    });
+  });
+});
@@ -22,7 +22,8 @@
 // live only in the pending seed draft, so there is no live path to hand the
 // query to. It is REFUSED — `INVALID_FILTER` / 400, the envelope this package's
 // `where` door already speaks — and never answered true. See
-// PREVIEW_FIELD_OPERATORS.
+// PREVIEW_FIELD_OPERATORS. [#19835] So is a field constraint carrying ZERO
+// operators (`{ name: {} }`), at any depth — see isEmptyFieldConstraint.
 
 import {
   calendarPartsInTzOrUtc,
@@ -193,6 +194,66 @@ function previewUnevaluableOperatorError(op: string, field: string): Error {
   );
 }
 
+/**
+ * [#19835] Is this field spec `{}` — a field constrained by ZERO operators?
+ *
+ * A plain object with no own enumerable keys, and nothing else — the predicate
+ * `driver-memory`, `driver-mongodb`, `driver-sql` and `@objectstack/formula`
+ * each apply under the same name. A `Date`, a `RegExp` or a class instance also
+ * enumerates to nothing, but it is a COMPARAND rather than a constraint, so the
+ * prototype check keeps it out of this refusal exactly as it does there.
+ *
+ * Mirrored locally, not imported: the exported copy lives in `driver-memory`
+ * (`filter-refusal.ts`), a package this service does not depend on, and a
+ * dependency on a driver for a four-line predicate is the wrong direction.
+ */
+function isEmptyFieldConstraint(spec: unknown): boolean {
+  if (spec === null || typeof spec !== 'object' || Array.isArray(spec)) return false;
+  const proto = Object.getPrototypeOf(spec);
+  if (proto !== Object.prototype && proto !== null) return false;
+  return Object.keys(spec as Row).length === 0;
+}
+
+/**
+ * [#19835] `{ field: {} }` — a field constrained by ZERO operators — REFUSED,
+ * in the same `INVALID_FILTER` / 400 envelope as
+ * {@link previewUnevaluableOperatorError}.
+ *
+ * ⛔ It used to MATCH EVERY ROW, and not by anyone's decision: the per-field
+ * loop in {@link matchesWhere} iterates the constraint's entries, an empty
+ * object has none, so the loop body never ran and the row fell through to the
+ * function's closing `return true`. The operator-vocabulary refusal (#19810)
+ * could not reach it either — with no key there is no operator to look up and
+ * no lookup to fail.
+ *
+ * Every shipped backend already refuses this shape (#5240 ruled it: refused
+ * everywhere, one wording): `driver-memory`'s and `driver-mongodb`'s
+ * `emptyFieldConstraintError`, and `driver-sql`'s at the top level and inside
+ * `$and`/`$or`/`$not` alike. This package's own `where` door refuses it too
+ * (`filter-normalizer`'s wrapper arm). So the draft preview charted every row
+ * for a filter publish never answers at all — the preview/publish divergence
+ * this evaluator's other refusals exist to make visible.
+ *
+ * ⛔ Refused, NOT answered as "matches nothing". `{ status: {} }` does not mean
+ * "no rows" — read literally it means "rows whose status is anything", and the
+ * shape is almost always an authoring accident (a filter builder that recorded
+ * a field and never its operator). Either silent reading hands the author a row
+ * count they never asked for; only the refusal names the constraint to repair.
+ *
+ * The message follows the drivers' wording (constraint, position, the two legal
+ * repairs) and carries no tracker number, per the runtime-string rule.
+ */
+function previewEmptyFieldConstraintError(field: string, path: string): Error {
+  return invalidFilterError(
+    `[analytics] Field constraint at ${path} carries zero operators ({ "${field}": {} }). A field ` +
+      `constraint must name at least one operator (e.g. { "${field}": { "$eq": "value" } }) or be a ` +
+      `direct comparand (e.g. { "${field}": "value" }). It is refused rather than evaluated: the ` +
+      `draft-data preview used to answer it with EVERY row, while every data driver and the live ` +
+      `analytics filter refuse it — so the drafted chart was drawn over rows the published one never ` +
+      `returns. It does not mean "no rows" either; name the operator the constraint was meant to carry.`,
+  );
+}
+
 /**
  * [#19810] Refuse a `where` this face cannot evaluate BEFORE any row is read.
  *
@@ -206,17 +267,30 @@ function previewUnevaluableOperatorError(op: string, field: string): Error {
  *
  * It mirrors {@link matchesWhere}'s own traversal exactly, malformed shapes
  * included — a non-array `$and` is left for `matchesWhere` to fault on as it
- * always has, so this gate widens no refusal beyond the operator vocabulary.
+ * always has, so this gate widens no refusal beyond the operator vocabulary
+ * and the zero-operator constraint.
+ *
+ * [#19835] The zero-operator constraint is judged HERE, for the whole tree,
+ * rather than only where {@link matchesWhere} meets it: that walk
+ * short-circuits (`every`/`some`, and a node returns on its first false entry),
+ * so a `{ $or: [{ name: 'Globex' }, { amount: {} }] }` would refuse or answer
+ * depending on which ROW was being tested. A malformed filter is refused for
+ * every row or none — the posture `@objectstack/formula`'s `assertFilterShape`
+ * takes for the same shape — and nesting under `$and`/`$or`/`$not` cannot
+ * route around it, the position `driver-sql` once dropped it in.
  */
-function assertPreviewCanEvaluate(where: Record<string, unknown> | undefined): void {
+function assertPreviewCanEvaluate(where: Record<string, unknown> | undefined, path = 'where'): void {
   if (!where) return;
   for (const [key, cond] of Object.entries(where)) {
+    const here = `${path}.${key}`;
     if (key === '$and' || key === '$or') {
-      if (Array.isArray(cond)) for (const arm of cond) assertPreviewCanEvaluate(arm as Row);
+      if (Array.isArray(cond)) cond.forEach((arm, i) => assertPreviewCanEvaluate(arm as Row, `${here}[${i}]`));
     } else if (key === '$not') {
       if (cond !== null && typeof cond === 'object' && !Array.isArray(cond)) {
-        assertPreviewCanEvaluate(cond as Row);
+        assertPreviewCanEvaluate(cond as Row, here);
       }
+    } else if (isEmptyFieldConstraint(cond)) {
+      throw previewEmptyFieldConstraintError(key, here);
     } else if (cond !== null && typeof cond === 'object' && !Array.isArray(cond)) {
       for (const op of Object.keys(cond as Row)) {
         if (!PREVIEW_FIELD_OPERATORS.has(op)) throw previewUnevaluableOperatorError(op, key);
@@ -240,6 +314,11 @@ export function matchesWhere(row: Row, where: Record<string, unknown> | undefine
       if (!(cond as Row[]).some((c) => matchesWhere(row, c as Row))) return false;
     } else if (key === '$not') {
       if (matchesWhere(row, cond as Row)) return false;
+    } else if (isEmptyFieldConstraint(cond)) {
+      // [#19835] Zero entries would leave the loop below unrun and fall through
+      // to a MATCH. Refused here too, so a direct caller of this matcher gets
+      // the same answer the row-independent gate gives a whole query.
+      throw previewEmptyFieldConstraintError(key, key);
     } else if (cond !== null && typeof cond === 'object' && !Array.isArray(cond)) {
       for (const [op, expected] of Object.entries(cond as Row)) {
         if (!matchOp(row[key], op, expected, key)) return false;