SELECT
    cust_name,
    cust_contact,
    cust_email
FROM
    Customers
WHERE
    cust_state = 'MI'
UNION
SELECT
    cust_name,
    cust_contact,
    cust_email
FROM
    Customers
WHERE
    cust_state = 'IL'
ORDER BY
    cust_name
#不允许使用多条 ORDER BY 子句，order by子句只能存在于最后一条。