## to_days，unix_timestamp
### 說明
| 函數 | 說明 |
| --- | --- |
| to_days(date) | 返回公元0年到date的天數 |
| unix_timestamp(date)| 將日期轉換成時間戳 |
### 例子：查詢寶寶出生天數
```sql
SELECT
id,
baby_name,
baby_birthday,
(to_days(now()) - to_days(baby_birthday)) AS baby_dayage,
(unix_timestamp(now()) - unix_timestamp(baby_birthday))/86400 as baby_dayage1
FROM
baby;
```
