CREATE TABLE customer ( customer_id INTEGER NOT NULL,

customer_name VARCHAR (25) NOT NULL,

address_line_1 VARCHAR (200),

city VARCHAR (100),

state_province CHAR (25),

postal_code VARCHAR (50),

PRIMARY KEY (customer_id) ) ;

CREATE TABLE order_header ( order_id INTEGER NOT NULL,

order_date DATE,

customer_id INTEGER,

PRIMARY KEY (order_id),

CONSTRAINT order_fkey_customer_id FOREIGN KEY (customer_id) REFERENCES customer (customer_id)) ;

CREATE TABLE product ( product_id INTEGER NOT NULL,

product_name VARCHAR (200),

product_line VARCHAR (200),

product_price DECIMAL(19,2),

PRIMARY KEY (product_id) ) ;

CREATE TABLE order_line ( order_id INTEGER NOT NULL,

product_id INTEGER NOT NULL,

quantity INTEGER,

PRIMARY KEY (order_id,

product_id),

CONSTRAINT order_line_fkey_order_id FOREIGN KEY (order_id) REFERENCES order_header (order_id),

CONSTRAINT order_line_fkey_product_id FOREIGN KEY (product_id) REFERENCES product (product_id)) ;

Create a query that returns the orders for Dec 2019 with the following columns (one row per order). Hint: use a CASE statement

-- order_id

-- number_of_items (number of items in the order)

-- number_of_computers (number of computers in the order)