updates models and schema doc, adds final purchase related tables

MODELS.md

@@ -467,7 +467,7 @@ struct Purchase {
     id: String,
     items: Vec<LineItem>,
     state: PurchaseState,
-    purchased_by: Person,
+    purchased_by: Option<Person>,
     purchased_at: Option<chrono::DateTime>,
     fulfilled_by: Option<Person>,
     fulfilled_at: Option<chrono::DateTime>,

SCHEMA.md

@@ -910,3 +910,57 @@ CREATE TABLE CouponCodeSkus (
 	CONSTRAINT CouponCodeSkus_FK_1 FOREIGN KEY (sku_id) REFERENCES Skus(id)
 );
 ```
+
+# Purchases
+The Purchases table will contain Purchases!
+
+``` sql
+CREATE TABLE Purchases (
+	id TEXT(36),
+	state TEXT,
+	purchased_by TEXT(36),
+	purchased_at INTEGER,
+	fulfilled_by TEXT(36),
+	fulfilled_at INTEGER,
+	total_charge NUMERIC DEFAULT (0.00),
+	CONSTRAINT Purchases_PK PRIMARY KEY (id),
+	CONSTRAINT Purchases_FK FOREIGN KEY (purchased_by) REFERENCES Persons(id),
+	CONSTRAINT Purchases_FK_1 FOREIGN KEY (fulfilled_by) REFERENCES Persons(id)
+);
+CREATE INDEX Purchases_state_IDX ON Purchases (state);
+CREATE INDEX Purchases_purchased_by_IDX ON Purchases (purchased_by);
+CREATE INDEX Purchases_purchased_at_IDX ON Purchases (purchased_at);
+CREATE INDEX Purchases_fulfilled_by_IDX ON Purchases (fulfilled_by);
+CREATE INDEX Purchases_fulfilled_at_IDX ON Purchases (fulfilled_at);
+CREATE INDEX Purchases_total_charge_IDX ON Purchases (total_charge);
+```
+
+# PurchaseLineItems
+The PurchaseLineItems table will relate a Purchase to one or more LineItems.
+
+``` sql
+CREATE TABLE PurchaseLineItems (
+	purchase_id TEXT(36),
+	line_item_id TEXT(36),
+	CONSTRAINT PurchaseLineItems_PK PRIMARY KEY (purchase_id,line_item_id),
+	CONSTRAINT PurchaseLineItems_FK FOREIGN KEY (purchase_id) REFERENCES Purchases(id),
+	CONSTRAINT PurchaseLineItems_FK_1 FOREIGN KEY (line_item_id) REFERENCES LineItems(id) ON DELETE CASCADE
+);
+CREATE INDEX PurchaseLineItems_purchase_id_IDX ON PurchaseLineItems (purchase_id);
+CREATE INDEX PurchaseLineItems_line_item_id_IDX ON PurchaseLineItems (line_item_id);
+```
+
+# PurchaseCouponCodes
+The PurchaseCouponCodes table will relate a Purchase to one or more CouponCodes that were successfully applied to the Purchase.
+
+``` sql
+CREATE TABLE PurchaseCouponCodes (
+	purchase_id TEXT(36),
+	coupon_code_id TEXT(36),
+	CONSTRAINT PurchaseCouponCodes_PK PRIMARY KEY (purchase_id,coupon_code_id),
+	CONSTRAINT PurchaseCouponCodes_FK FOREIGN KEY (purchase_id) REFERENCES Purchases(id),
+	CONSTRAINT PurchaseCouponCodes_FK_1 FOREIGN KEY (coupon_code_id) REFERENCES CouponCodes(id)
+);
+CREATE INDEX PurchaseCouponCodes_purchase_id_IDX ON PurchaseCouponCodes (purchase_id);
+CREATE INDEX PurchaseCouponCodes_coupon_code_id_IDX ON PurchaseCouponCodes (coupon_code_id);
+```