SELECT product_type_code FROM Products GROUP BY product_type_code HAVING count(*)  >=  2
What are the product type code with at least two products?
CREATE TABLE `Products` (
`product_id` INTEGER PRIMARY KEY,
`product_type_code` VARCHAR(15),
`product_name` VARCHAR(80),
`product_price` DOUBLE NULL
);
CREATE TABLE `Addresses` (
`address_id` INTEGER PRIMARY KEY,
`address_details` VARCHAR(255)
);
CREATE TABLE `Customers` (
`customer_id` INTEGER PRIMARY KEY,
`address_id` INTEGER NOT NULL,
`payment_method_code` VARCHAR(15),
`customer_number` VARCHAR(20),
`customer_name` VARCHAR(80),
`customer_address` VARCHAR(255),
`customer_phone` VARCHAR(80),
`customer_email` VARCHAR(80)
);
CREATE TABLE `Customer_Orders` (
`order_id` INTEGER PRIMARY KEY,
`customer_id` INTEGER NOT NULL,
`order_date` DATETIME NOT NULL,
`order_status_code` VARCHAR(15),
FOREIGN KEY (`customer_id` ) REFERENCES `Customers`(`customer_id` )
);
CREATE TABLE `Order_Items` (
`order_item_id` INTEGER NOT NULL ,
`order_id` INTEGER NOT NULL,
`product_id` INTEGER NOT NULL,
`order_quantity` VARCHAR(80),
FOREIGN KEY (`order_id` ) REFERENCES `Customer_Orders`(`order_id` ),
FOREIGN KEY (`product_id` ) REFERENCES `Products`(`product_id` )
);
INSERT INTO Addresses (`address_id`, `address_details`) VALUES (1, '2632 Ofelia Stream Apt. 537
INSERT INTO Products (`product_id`, `product_type_code`, `product_name`, `product_price`) VALUES (1, 'Hardware', 'Monitor', '2084.944172129')
INSERT INTO Customers (`customer_id`, `address_id`, `payment_method_code`, `customer_number`, `customer_name`, `customer_address`, `customer_phone`, `customer_email`) VALUES (1, 9, 'Credit Card', '601', 'Jeromy', '422 Bode Mount Apt. 688', '1-968-453-3485', 'everett.kautzer@example.com')
INSERT INTO Customer_Orders (`order_id`, `customer_id`, `order_date`, `order_status_code`) VALUES (1, 12, '2016-05-14 22:08:41', 'Part')
INSERT INTO Order_Items (`order_item_id`, `order_id`, `product_id`, `order_quantity`) VALUES (1, 8, 13, '2')