org.bom_items

The composition that links input materials and/or input SKUs (with quantities) to an output SKU. One row per (output SKU × input). Polymorphic on the input side because materials and SKUs are kept separate.

ER diagram

Columns

Column	Type	Notes
id	UUID PK
org_id	UUID FK	→ platform.organizations(id).
sku_id	UUID FK	NOT NULL. → org.skus(id) ON DELETE CASCADE. The output SKU this BOM produces.
material_id	UUID FK	→ org.materials(id) ON DELETE RESTRICT. Input — XOR with input_sku_id.
input_sku_id	UUID FK	→ org.skus(id) ON DELETE RESTRICT. Input — XOR with material_id. (FG-as-input.)
quantity	NUMERIC(18,6)	NOT NULL. CHECK > 0. Decimals allowed.
created_at	TIMESTAMPTZ	NOT NULL. Default NOW().

Rows are immutable — no updated_at. Recipe changes are delete-and-replace.

Constraints

• Input XOR: ((material_id IS NOT NULL AND input_sku_id IS NULL) OR (material_id IS NULL AND input_sku_id IS NOT NULL)). Exactly one of the two input FKs is set.
• No self-reference: input_sku_id IS NULL OR input_sku_id <> sku_id.
• UNIQUE (sku_id, COALESCE(material_id, input_sku_id)) — one row per (output SKU, input).

Cross-references

• Output side: every row's sku_id is one of the SKUs.
• Input side: each row references either a material or another SKU.
• BOMs drive cost cascades and WO consumption logic in L3.
• Snapshotted into work_order_inputs at WO creation.