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SQL 通用數(shù)據(jù)類型
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SQL DB 數(shù)據(jù)類型
MySQL EXTRACT() 函數(shù)
MySQL Date 函數(shù)定義和用法
EXTRACT() 函數(shù)用于返回日期/時(shí)間的單獨(dú)部分，比如年、月、日、小時(shí)、分鐘等等。
語法
EXTRACT(unit FROM date)
date 參數(shù)是合法的日期表達(dá)式。unit 參數(shù)可以是下列的值：
| Unit 值 |
|---|
| MICROSECOND |
| SECOND |
| MINUTE |
| HOUR |
| DAY |
| WEEK |
| MONTH |
| QUARTER |
| YEAR |
| SECOND_MICROSECOND |
| MINUTE_MICROSECOND |
| MINUTE_SECOND |
| HOUR_MICROSECOND |
| HOUR_SECOND |
| HOUR_MINUTE |
| DAY_MICROSECOND |
| DAY_SECOND |
| DAY_MINUTE |
| DAY_HOUR |
| YEAR_MONTH |
實(shí)例
假設(shè)我們有如下的 "Orders" 表：
| OrderId | ProductName | OrderDate |
|---|---|---|
| 1 | Jarlsberg Cheese | 2008-11-11 13:23:44.657 |
下面是 SELECT 語句：
SELECT EXTRACT(YEAR FROM OrderDate) AS OrderYear,
EXTRACT(MONTH FROM OrderDate) AS OrderMonth,
EXTRACT(DAY FROM OrderDate) AS OrderDay
FROM Orders
WHERE OrderId=1
EXTRACT(MONTH FROM OrderDate) AS OrderMonth,
EXTRACT(DAY FROM OrderDate) AS OrderDay
FROM Orders
WHERE OrderId=1
結(jié)果如下所示：
| OrderYear | OrderMonth | OrderDay |
|---|---|---|
| 2008 | 11 | 11 |
MySQL Date 函數(shù)其他擴(kuò)展