EXTRACT() 提取函数

EXTRACT() 函数用于提取日期/时间的单独部分，比如年、月、日、小时、分钟等等。 示例：

select created_at, EXTRACT (YEAR FROM created_at) AS year, EXTRACT (MONTH FROM created_at) AS month, EXTRACT (DAY FROM created_at) AS day, EXTRACT (HOUR FROM created_at) AS hour, EXTRACT (MINUTE FROM created_at) AS MINUTE, EXTRACT (SECOND FROM created_at) AS SECOND from company_contract