今天陪着父母去迪沙鲁，唠唠家常，慢慢驾驶，细细品尝当下，人们总说与家人相处，时间就会较为真实，否者就会有种失重感。感受不到活着的证据
接着就去再也吃晚餐，谈笑风生，食髓知味。。。
Candidate key that has not been chosen to act as the primary key of the vehicle table is called an alternate key.
It’s important to remember that a primary key can be composed of one single simple attribute or multiple attributes (a composite key), which is composed of two or more attributes that form a unique value in each row of the table. This usually happens when a single attribute cannot be found to act as a primary key.
