SQL CURRENT_TIMESTAMP

SQL Server CURRENT_TIMESTAMP 函数是日期和时间函数之一，用于返回服务器实例运行所在计算机的当前时间戳（日期和时间）。CURRENT_TIMESTAMP 的基本语法如下：

CURRENT_TIMESTAMP

对于这个 CURRENT_TIMESTAMP 函数的示例，我们将使用下面显示的数据

Employee Table 1

SQL CURRENT_TIMESTAMP 示例

CURRENT_TIMESTAMP 函数返回 DateTime 数据类型，格式为：“yyyy-mm-dd hh:mm:ss.nnn”（您可以看到，小数秒精度 = 3）。

SELECT CURRENT_TIMESTAMP AS [Current_Date]
Current Date 2

CURRENT_TIMESTAMP 示例 2

在此示例中，我们将向您展示 CURRENT_TIMESTAMP 的示例。

SELECT 'Today' AS 'TODAY', CURRENT_TIMESTAMP AS [Current_Date];

SELECT 'Milli Seconds' AS 'MILLI', DATEPART(millisecond, CURRENT_TIMESTAMP) AS [Milli_Seconds]; 
SELECT 'Micro Seconds' AS 'MICRO', DATEPART(microsecond, CURRENT_TIMESTAMP) AS [Micro_Seconds]; 
SELECT 'Nano Seconds' AS 'NANO', DATEPART(nanosecond, CURRENT_TIMESTAMP) AS [Nano_Seconds]; 

SELECT 'Day' AS 'DAY', DATENAME(WEEKDAY, CURRENT_TIMESTAMP) AS [Day_Name]; 

SELECT 'Tomorrow' AS 'DAY', DATEADD(day, 1, CURRENT_TIMESTAMP) AS [Next_Date];
CURRENT TIME STAMP Example 3

我们使用 DATEPART 函数从 SQL Server 当前时间戳（今天的日期和时间）中显示毫秒、微秒和纳秒。

SELECT 'Milli Seconds' AS 'MILLI', DATEPART(millisecond, CURRENT_TIMESTAMP) AS [Milli_Seconds]; 
SELECT 'Micro Seconds' AS 'MICRO', DATEPART(microsecond, CURRENT_TIMESTAMP) AS [Micro_Seconds]; 
SELECT 'Nano Seconds' AS 'NANO', DATEPART(nanosecond, CURRENT_TIMESTAMP) AS [Nano_Seconds];

接下来，我们使用 DATENAME 函数从当前时间戳（今天的日期和时间）中显示星期几。

SELECT 'Day' AS 'DAY', DATENAME(WEEKDAY, CURRENT_TIMESTAMP) AS [Day_Name];

最后，我们使用 DATEADD 函数显示明天的日期戳。

SELECT 'Tomorrow' AS 'DAY', DATEADD(day, 1, CURRENT_TIMESTAMP) AS [Next_Date];

SQL Server CURRENT_TIMESTAMP 示例 3

在此 日期和时间函数 示例中，我们使用 SQL DATEDIFF 函数。它查找当前时间戳与“入职日期”之间的差异，以检查员工详细信息。例如，他是在哪一年入职的，他为公司工作了多少周等等。

SELECT [EmpID]
      ,[FirstName] + ' '+ [LastName] AS [Full Name]
      ,[Occupation]
      ,[YearlyIncome]
      ,[HireDate]
      ,DATEDIFF (year, [HireDate], CURRENT_TIMESTAMP) AS [YEARS]
      ,DATEDIFF (day, [HireDate], CURRENT_TIMESTAMP) AS [DAYS]
      ,DATEDIFF (WEEK, [HireDate], CURRENT_TIMESTAMP) AS [WEEKS]
      ,DATEDIFF (WEEKDAY, [HireDate], CURRENT_TIMESTAMP) AS [WEEKDAY]
  FROM [Employee]

在这里，我们使用 DATEDIFF 函数查找员工入职日期与当前今天的日期和时间（CURRENT_TIMESTAMP）之间的差异。

CURRENT_TIMESTAMP Function 4