Removed diff.sql

Patch file only for updating. Shouldn't clutter file system after that.

diff.sql

-/*
- * This file is to patch up an already existing SQLite file
- * to use the new product diffing system
- */
-CREATE TABLE diff_help (
-    id INTEGER PRIMARY KEY NOT NULL,
-    product_id INTEGER NOT NULL,
-    amount INTEGER,
-
-    FOREIGN KEY (product_id) REFERENCES products(id)
-);
-
-CREATE VIEW diff_view AS
-SELECT d.id AS id,
-       p.id AS product_id,
-       p.sale_status AS sale_status,
-       -- visible border
-       p.name AS name,
-       s.active AS expected,
-       d.amount AS actual,
-       d.amount - s.active AS diff
-FROM products p
-INNER JOIN stock s ON p.id = s.product_id
-INNER JOIN diff_help d ON p.id = d.product_id;
-
-CREATE TRIGGER after_diff_help_delete_last
-AFTER DELETE ON diff_help
-FOR EACH ROW
-WHEN (SELECT count (1) = 0 FROM diff_help)
-BEGIN
-    INSERT INTO diff_help (product_id)
-    SELECT id FROM products p;
-END;
-
-CREATE TRIGGER diff_view_transfer
-INSTEAD OF DELETE ON diff_view
-BEGIN
-    UPDATE stock SET active = OLD.actual
-    WHERE OLD.actual IS NOT NULL
-      AND product_id = OLD.product_id;
-
-    INSERT INTO stock_diff (product_id, expected, actual)
-    SELECT OLD.product_id, OLD.expected, OLD.actual
-     WHERE OLD.actual IS NOT NULL;
-
-    DELETE FROM diff_help WHERE id = OLD.id;
-END;
-
-CREATE TRIGGER update_view_trigger
-INSTEAD OF UPDATE ON diff_view
-BEGIN
-    UPDATE diff_help SET amount = NEW.actual WHERE id = NEW.id;
-END;
-
-INSERT INTO diff_help (product_id)
-SELECT id FROM products LIMIT 1;
-DELETE FROM diff_help;