Some more tables and using views in query

app/Migrations/create-schema.sql

@@ -38,6 +38,27 @@ CREATE TABLE IF NOT EXISTS orders (
 --------------------------------------------
 -- Recipe/Cookie related tables
 --------------------------------------------
+-- Notes: the unit type can be defined in terms 
+-- of volume or weight instead. Here we choose 
+-- to use static si-prefixes in relevant tables.
+
+-- What types of ingredients do we handle
+CREATE TABLE IF NOT EXISTS ingredients (
+    ingredient_id INTEGER PRIMARY KEY,
+    ingredient_name VARCHAR(50) NOT NULL UNIQUE,
+    preferred_unit VARCHAR(50) NOT NULL CHECK (preferred_unit IN ('g', 'ml'))
+);
+
+-- What ingredients are in what cookies
+CREATE TABLE IF NOT EXISTS recipe_contents (
+    cookie_id INT NOT NULL,
+    ingredient_id INT NOT NULL,
+    quantity INT NOT NULL,
+    unit VARCHAR(50) NOT NULL CHECK (unit IN ('g', 'ml')),
+    PRIMARY KEY (cookie_id, ingredient_id),
+    FOREIGN KEY (cookie_id) REFERENCES cookies(cookie_id),
+    FOREIGN KEY (ingredient_id) REFERENCES ingredients(ingredient_id)
+);
 
 -- Describes ingredients and stock.
 CREATE TABLE IF NOT EXISTS raw_materials (
@@ -66,12 +87,28 @@ CREATE TABLE IF NOT EXISTS raw_materials_deliveries (
 CREATE TABLE IF NOT EXISTS pallets (
     pallet_id INTEGER PRIMARY KEY,
     cookie_id INT NOT NULL,
-    -- order_id INT NOT NULL,
+    order_id INT, -- This should be not null
     status VARCHAR(50) NOT NULL CHECK (status IN ('freezer', 'delivered', 'blocked')),
     production_date DATE NOT NULL,
     delivery_date DATE DEFAULT NULL,
     FOREIGN KEY (cookie_id) REFERENCES cookies(cookie_id)
-    -- FOREIGN KEY (order_id) REFERENCES orders(order_id)
+    FOREIGN KEY (order_id) REFERENCES orders(order_id)
 );
 
+--------------------------------------------
+-- Views
+--------------------------------------------
+
+-- Pallet
+CREATE VIEW IF NOT EXISTS pallets_view AS
+SELECT 
+    pallet_id,
+    cookie_name,
+    order_id,
+    status,
+    production_date,
+    delivery_date
+FROM pallets
+JOIN cookies ON pallets.cookie_id = cookies.cookie_id;
+
 PRAGMA foreign_keys = ON;

app/src/main/java/krusty/Database.java

@@ -127,7 +127,7 @@ public class Database {
 		try {
 			Statement stmt = conn.createStatement();
 			StringBuilder query = new StringBuilder(
-					"SELECT cookie_name, status FROM pallets JOIN cookies ON pallets.cookie_id = cookies.cookie_id");
+					"SELECT cookie_name, status FROM pallets_view");
 
 			// r is validated here
 			if (r.isPresent()) {