SELECT STD(orderCount) FROM (SELECT customerNumber, count(*) orderCount FROM orders GROUP BY customerNumber) t;
SELECT STDDEV_SAMP(orderCount) FROM (SELECT customerNumber, count(*) orderCount FROM orders WHERE status = 'Shipped' GROUP BY customerNumber) t;
SELECT * FROM customers;
SELECT * FROM employees;
SELECT * FROM offices;
SELECT * FROM orderdetails;
SELECT * FROM orders;
SELECT * FROM payments;
SELECT * FROM productlines;
SELECT * FROM products;