How to wait for 2 seconds?

How does one cause a delay in execution for a specified number of seconds?

This doesn't do it:

WAITFOR DELAY '00:02';

What is the correct format?

The documentation for WAITFOR() doesn't explicitly lay out the required string format.

This will wait for 2 seconds:

WAITFOR DELAY '00:00:02';

The format is hh:mi:ss.mmm.

As mentioned in other answers, all of the following will work for the standard string-based syntax.

WAITFOR DELAY '02:00' --Two hours
WAITFOR DELAY '00:02' --Two minutes
WAITFOR DELAY '00:00:02' --Two seconds
WAITFOR DELAY '00:00:00.200' --Two tenths of a seconds

There is also an alternative method of passing it a DATETIME value. You might think I'm confusing this with WAITFOR TIME, but it also works for WAITFOR DELAY.

Considerations for passing DATETIME:

• It must be passed as a variable, so it isn't a nice one-liner anymore.
• The delay is measured as the time since the Epoch ('1900-01-01').
• For situations that require a variable amount of delay, it is much easier to manipulate a DATETIME than to properly format a VARCHAR.

How to wait for 2 seconds:

--Example 1
DECLARE @Delay1 DATETIME
SELECT @Delay1 = '1900-01-01 00:00:02.000'
WAITFOR DELAY @Delay1

--Example 2
DECLARE @Delay2 DATETIME
SELECT @Delay2 = dateadd(SECOND, 2, convert(DATETIME, 0))
WAITFOR DELAY @Delay2

A note on waiting for TIME vs DELAY:

Have you ever noticed that if you accidentally pass WAITFOR TIME a date that already passed, even by just a second, it will never return? Check it out:

--Example 3
DECLARE @Time1 DATETIME
SELECT @Time1 = getdate()
WAITFOR DELAY '00:00:01'
WAITFOR TIME @Time1 --WILL HANG FOREVER

Unfortunately, WAITFOR DELAY will do the same thing if you pass it a negative DATETIME value (yes, that's a thing).

--Example 4
DECLARE @Delay3 DATETIME
SELECT @Delay3 = dateadd(SECOND, -1, convert(DATETIME, 0))
WAITFOR DELAY @Delay3 --WILL HANG FOREVER

However, I would still recommend using WAITFOR DELAY over a static time because you can always confirm your delay is positive and it will stay that way for however long it takes your code to reach the WAITFOR statement.

How about this?

WAITFOR DELAY '00:00:02';

If you have "00:02" it's interpreting that as Hours:Minutes.

Try this example:

exec DBMS_LOCK.sleep(5);

This is the whole script:

SELECT TO_CHAR (SYSDATE, 'MM-DD-YYYY HH24:MI:SS') "Start Date / Time" FROM DUAL;

exec DBMS_LOCK.sleep(5);

SELECT TO_CHAR (SYSDATE, 'MM-DD-YYYY HH24:MI:SS') "End Date / Time" FROM DUAL;