text: CREATE TABLE quantity_unit_conversions (
  	id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
  	from_qu_id INT NOT NULL,
  	to_qu_id INT NOT NULL,
  	factor REAL NOT NULL,
  	product_id INT,
  	row_created_timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
  );
  
  CREATE TRIGGER quantity_unit_conversions_custom_unique_constraint_INS BEFORE INSERT ON quantity_unit_conversions
  BEGIN
  -- Necessary because unique constraints don't include NULL values in SQLite, and also because the constraint should include the products default conversion factor
  SELECT CASE WHEN((
  	SELECT 1
  	FROM quantity_unit_conversions
  	WHERE from_qu_id = NEW.from_qu_id
  		AND to_qu_id = NEW.to_qu_id
  		AND IFNULL(product_id, 0) = IFNULL(NEW.product_id, 0)
  	UNION
  	SELECT 1
  	FROM products
  	WHERE id = NEW.product_id
  		AND qu_id_purchase = NEW.from_qu_id
  		AND qu_id_stock = NEW.to_qu_id
  	)
  	NOTNULL) THEN RAISE(ABORT, "Unique constraint violation") END;
  END;
  
  CREATE TRIGGER quantity_unit_conversions_custom_unique_constraint_UPD BEFORE UPDATE ON quantity_unit_conversions
  BEGIN
  -- Necessary because unique constraints don't include NULL values in SQLite, and also because the constraint should include the products default conversion factor
  SELECT CASE WHEN((
  	SELECT 1
  	FROM quantity_unit_conversions
  	WHERE from_qu_id = NEW.from_qu_id
  		AND to_qu_id = NEW.to_qu_id
  		AND IFNULL(product_id, 0) = IFNULL(NEW.product_id, 0)
  		AND id != NEW.id
  	UNION
  	SELECT 1
  	FROM products
  	WHERE id = NEW.product_id
  		AND qu_id_purchase = NEW.from_qu_id
  		AND qu_id_stock = NEW.to_qu_id
  	)
  	NOTNULL) THEN RAISE(ABORT, "Unique constraint violation") END;
  END;
  
  CREATE VIEW quantity_unit_conversions_resolved
  AS
  -- First: Product "purchase to stock" conversion factor
  SELECT
  	p.id AS id, -- Dummy, LessQL needs an id column
  	p.id AS product_id,
  	p.qu_id_purchase AS from_qu_id,
  	qu_from.name AS from_qu_name,
  	p.qu_id_stock AS to_qu_id,
  	qu_to.name AS to_qu_name,
  	p.qu_factor_purchase_to_stock AS factor
  FROM products p
  JOIN quantity_units qu_from
  	ON p.qu_id_purchase = qu_from.id
  JOIN quantity_units qu_to
  	ON p.qu_id_stock = qu_to.id
  
  UNION
  
  -- Second: Product specific overrides
  SELECT
  	p.id AS id, -- Dummy, LessQL needs an id column
  	p.id AS product_id,
  	quc.from_qu_id AS from_qu_id,
  	qu_from.name AS from_qu_name,
  	quc.to_qu_id AS to_qu_id,
  	qu_to.name AS to_qu_name,
  	quc.factor AS factor
  FROM products p
  JOIN quantity_unit_conversions quc
  	ON p.qu_id_stock = quc.from_qu_id
  	AND p.id = quc.product_id
  JOIN quantity_units qu_from
  	ON quc.from_qu_id = qu_from.id
  JOIN quantity_units qu_to
  	ON quc.to_qu_id = qu_to.id
  
  UNION
  
  -- Third: Default quantity unit conversion factors
  SELECT
  	p.id AS id, -- Dummy, LessQL needs an id column
  	p.id AS product_id,
  	p.qu_id_stock AS from_qu_id,
  	qu_from.name AS from_qu_name,
  	quc.to_qu_id AS to_qu_id,
  	qu_to.name AS to_qu_name,
  	quc.factor AS factor
  FROM products p
  JOIN quantity_unit_conversions quc
  	ON p.qu_id_stock = quc.from_qu_id
  	AND quc.product_id IS NULL
  JOIN quantity_units qu_from
  	ON quc.from_qu_id = qu_from.id
  JOIN quantity_units qu_to
  	ON quc.to_qu_id = qu_to.id;
  
  DROP TRIGGER cascade_change_qu_id_stock;
  CREATE TRIGGER cascade_change_qu_id_stock AFTER UPDATE ON products
  BEGIN
  	UPDATE recipes_pos
  	SET qu_id = NEW.qu_id_stock
  	WHERE product_id = NEW.id
  		AND qu_id = OLD.qu_id_stock;
  END;
  