UNIX_TIMESTAMP in SQL Server

Question

I need to create a function in SQL Server 2008 that will mimic mysql's UNIX_TIMESTAMP().

Answer 1

If you're not bothered about dates before 1970, or millisecond precision, just do:

-- SQL Server
SELECT DATEDIFF(s, '1970-01-01 00:00:00', DateField)

Almost as simple as MySQL's built-in function:

-- MySQL
SELECT UNIX_TIMESTAMP(DateField);

Other languages (Oracle, PostgreSQL, etc): How to get the current epoch time in ...

---

If you need millisecond precision (SQL Server 2016/13.x and later):

SELECT DATEDIFF_BIG(ms, '1970-01-01 00:00:00', DateField)