DROP TABLE products_prices;
CREATE TABLE products_prices (
  id INT(11) AUTO_INCREMENT PRIMARY KEY,
  target_date DATE COMMENT "仕入日",
  product_id INT(11) COMMENT "製品モデル",
  price DECIMAL(16,3) COMMENT "単価",
  created_at DATETIME COMMENT "作成日時",
  updated_at DATETIME COMMENT "更新日時"
);

CREATE INDEX product_id ON products_prices (product_id);
CREATE INDEX target_date ON products_prices (target_date);
