编写正确的 SQL 语句，从 customers 表中选择 city 值为 "Berlin" 的所有记录。
SELECT * FROM customers @(21);
SELECT * FROM customers WHERE city = 'Berlin';
SELECT * FROM customers WHERE city ='Berlin';
SELECT * FROM customers WHERE city = 'Berlin';
SELECT * FROM customers WHERE city ='Berlin';
SELECT * FROM customers WHERE city LIKE 'Berlin';
SELECT * FROM customers WHERE city='Berlin';