Domain Model

Pricing owns no schema. All tables below are defined in @nx/core under packages/core/src/models/schemas/pricing/, in the PostgreSQL pricing schema. Pricing re-exports them as repositories.

1. Full ERD

2. Entities

One block per table. Schema source: packages/core/src/models/schemas/pricing/.

FareSet

Property	Value
Table	pricing.FareSet
Source	core/src/models/schemas/pricing/fare-set/schema.ts
Soft-delete	yes
Owner ID column	productVariantId (soft ref, no FK)

Fields: id, name (i18n), description (i18n), status (default DEACTIVATED), productVariantId (not null), common columns.

Indexes: IDX on productVariantId, status.

Status enum — FareSetStatuses: ACTIVATED, DEACTIVATED. One ACTIVATED set per variant is the selection invariant.

Fare

Property	Value
Table	pricing.Fare
Source	core/src/models/schemas/pricing/fare/schema.ts
Soft-delete	yes

Fields:

Field	Type	Required	Default	Description
id	text	✓	Snowflake	PK
name / description	i18n jsonb		—	{ default, en, vi }
status	text	✓	ACTIVATED	FareStatuses
type	text		null	FareTypes.SALE / OVERRIDE / null (child)
effectiveFrom / effectiveTo	timestamptz		—	Effective window
minQuantity / maxQuantity	decimal(15,4)		—	Quantity gate
amount	decimal(15,4)		—	Price (null for OVERRIDE parent group)
rulesCount / childrenCount	integer		—	Denormalized counters
fareSetId	text	✓	—	Owning FareSet
parentId	text		null	Parent fare (group)

Indexes: IDX on fareSetId, parentId, status.

Relations: fareSet (M:1), parent (self M:1), children (1:M), fareRules (1:M via polymorphic Rule).

Status enum — FareStatuses: ACTIVATED, DEACTIVATED, ARCHIVED.

Rule

Property	Value
Table	pricing.Rule
Source	core/src/models/schemas/pricing/rule/schema.ts
Soft-delete	yes

Fields: polymorphic principalType / principalId, data-type value columns (tValue/nValue/bValue/jValue/boValue + dataType), attribute (not null), priority (not null), operator (not null).

Concept	Values
principalType (RulePrincipalTypes)	Fare, Promotion, PromotionMethod
operator (RuleOperators)	EQ, NE, NEQ, GT, GTE, LT, LTE, IN, INQ, NIN, CONTAINS
context (RuleContexts, in metadata)	source (buy rule), target (discount rule)

CONTAINS is the inverse of IN — context value is an array, rule value scalar. Used by the FBT override (orderProductVariantIds CONTAINS leadVariantId).

TaxSet

Property	Value
Table	pricing.TaxSet
Source	core/src/models/schemas/pricing/tax-set/schema.ts
Soft-delete	yes

Fields: polymorphic principalType / principalId, name (i18n), status (default ACTIVATED), sourceType, sourceId.

Indexes: unique-partial on (principalId, principalType, status) where deletedAt IS NULL; IDX on sourceId, (sourceType, sourceId), status.

principalType='ProductVariant' → item-level taxes; principalType='Merchant' → order-level taxes.

Tax

Field	Type	Required	Default	Description
name	i18n jsonb	✓	—	—
type	text		100_PERCENTAGE	TaxModes: AMOUNT / PERCENTAGE / PER_UNIT_AMOUNT
value	decimal(15,4)	✓	—	Rate or fixed amount
effectiveFrom	timestamptz	✓	—	—
effectiveTo	timestamptz		—	—
priority	integer		0	Ascending; same priority share a base
isInclusive	boolean	✓	false	Embedded in displayed price (back-calc)
shouldApplyOnDiscounted	boolean	✓	true	Discount-aware basis
isCompound	boolean	✓	true	Compounds on prior taxes
minQuantity / maxQuantity	decimal(15,4)		—	Quantity condition
usage	text	✓	000_SALE	TaxUsages.SALE / PURCHASE
chargeTarget	text	✓	000_CUSTOMER	CUSTOMER (on invoice) / MERCHANT (PIT)
taxSetId	text	✓	—	Owning TaxSet
taxTypeId	text		—	Classification
discriminationTypeId	text	✓	—	VN tax classification ref

Indexes: IDX on discriminationTypeId, status, taxSetId, taxTypeId.

TaxType

Property	Value
Table	pricing.TaxType
Source	core/src/models/schemas/pricing/tax-type/schema.ts

Fields: type (FixedTaxTypes: VAT, EXCISE, ENVIRONMENTAL, LUXURY, PIT, CUSTOM), name/description (i18n), chargeTarget, status, merchantId (nullable → system type).

Indexes: unique on (type, merchantId); IDX on merchantId, (merchantId, status).

Cost

Property	Value
Table	pricing.Cost
Source	core/src/models/schemas/pricing/cost/schema.ts

Fields: polymorphic principalType / principalId (getCurrentCost/getEffectiveCost hardcode ProductVariant), user-audit columns, amount (not null), note, effectiveFrom (not null), effectiveTo (nullable = current/open-ended).

Only one open-ended (null effectiveTo) cost per variant. Not yet wired into either calculator.

Promotion

Field	Type	Required	Default	Description
code	text		null	Null = auto-apply only
enableStacking	boolean	✓	true	—
isAutomatic	boolean	✓	false	—
isTaxInclusive	boolean	✓	false	—
name	i18n	✓	—	—
effectiveFrom / effectiveTo	timestamptz		—	—
type	text	✓	STANDARD	PromotionTypes
status	text	✓	DRAFT	PromotionStatuses
usageLimit / usageCount	integer		usageCount=0	—
rulesCount	integer	✓	0	Denormalized
merchantId	text		—	—

Indexes: unique-partial on code where deletedAt IS NULL; IDX on merchantId, (merchantId, status).

PromotionMethod

Fields: promotionId (not null), type (PromotionMethodType), value (not null), targetType (not null), allocation, currency (default VND), exchangeRate (default 1), maxQuantity, sourceRulesCount/targetRulesCount, BuyGet fields (buyGetTargetQuantity, buyGetSourceMinQuantity).

Indexes: unique-partial on promotionId where deletedAt IS NULL (one method per promotion).

3. Cross-entity Invariants

Invariant	Enforcement
Exactly one ACTIVATED FareSet per productVariantId	Worker idempotency + FareSetStatuses.canDeactivate() always false
OVERRIDE fare wins over default; else lowest-priced fare	PricingFareCalculatorService / FareCalculatorService selection
Child fares evaluated only when their AND-rules all pass	PricingRuleEvaluatorService (lodash get() attribute path)
Taxes within the same priority share a base; higher priorities compound	PricingTaxCalculatorService / TaxCalculatorService priority grouping
Inclusive tax back-calculated out of displayed price	tax calculator isInclusive branch
One open-ended Cost (effectiveTo IS NULL) per variant	CostService.updateCurrentCost closes prior before opening new
One PromotionMethod per Promotion	unique-partial index on promotionId
FBT override seeded at most once per (related FareSet, lead variant)	PricingWorkerService._isFbtOverrideAlreadySeeded

4. Soft-delete Behavior

Behavior	Detail
Read default	deletedAt IS NULL (model defaultFilter)
Hard-delete	Not used by default
Unique constraints	Partial — scoped WHERE deletedAt IS NULL (FareSet, TaxSet, Promotion code, PromotionMethod) so a soft-deleted row frees the slot

5. Related Pages

• Architecture
• Fare System
• Tax System
• Decisions