获取当前年：
select YEAR(NOW()) as `YEAR`获取当前月：
select MONTH(NOW()) as MONTH获取当前小时
select HOUR(NOW()) as HOUR获取当前分钟
select MINUTE(NOW()) as MINUTE获取当I前秒
select SECOND(NOW()) as SECOND获取当前季度
select QUARTER(NOW()) as QUARTER获取当前年：
select YEAR(NOW()) as `YEAR`获取当前月：
select MONTH(NOW()) as MONTH获取当前小时
select HOUR(NOW()) as HOUR获取当前分钟
select MINUTE(NOW()) as MINUTE获取当I前秒
select SECOND(NOW()) as SECOND获取当前季度
select QUARTER(NOW()) as QUARTER道可道，非常道；名可名，非常名。 无名，天地之始，有名，万物之母。 故常无欲，以观其妙，常有欲，以观其徼。 此两者，同出而异名，同谓之玄，玄之又玄，众妙之门。