选择 country 字段的值在以下列表中所有客户
('Norway', 'Sweden', 'Denmark')
SELECT * FROM customers WHERE country @(34);
SELECT * FROM customers WHERE country IN ('Norway', 'Sweden', 'Denmark');
SELECT * FROM customers WHERE country IN ('Norway','Sweden','Denmark');
SELECT * FROM customers WHERE country IN ('Norway', 'Sweden','Denmark');
SELECT * FROM customers WHERE country IN ('Norway','Sweden', 'Denmark');