From 3de3e03ab3f4a0d95adbbd0fbdf58391a50ce4c3 Mon Sep 17 00:00:00 2001
From: Bernd Bestel <bernd@berrnd.de>
Date: Sun, 21 Oct 2018 15:02:52 +0200
Subject: [PATCH] Created database logic for nested recipes (references #77)

---
 migrations/0043.sql | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 migrations/0043.sql

diff --git a/migrations/0043.sql b/migrations/0043.sql
new file mode 100644
index 00000000..795ce707
--- /dev/null
+++ b/migrations/0043.sql
@@ -0,0 +1,25 @@
+CREATE TABLE recipes_nestings (
+	id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
+	recipe_id INTEGER NOT NULL,
+	includes_recipe_id INTEGER NOT NULL,
+	row_created_timestamp DATETIME DEFAULT (datetime('now', 'localtime')),
+
+	UNIQUE(recipe_id, includes_recipe_id)
+);
+
+CREATE VIEW recipes_nestings_resolved
+AS
+WITH RECURSIVE r1(recipe_id, includes_recipe_id)
+AS (
+	SELECT id, id
+	FROM recipes
+	
+	UNION ALL
+	
+	SELECT rn.recipe_id, r1.includes_recipe_id
+	FROM recipes_nestings rn, r1 r1
+	WHERE rn.includes_recipe_id = r1.recipe_id
+	LIMIT 100 -- This is just a safety limit to prevent infinite loops due to infinite nested recipes
+)
+SELECT *
+FROM r1;