Datetime querying

Transact-SQL
1

Hi. I have a field in the format yyyy-mm-dd hh:mm e.g. 2018-01-01 00:00. How do I query the time element of this field?
e.g. select [object] where [answer] = '00:05'

thanks

SQL Server 2016

2

If fieldtype is datetime:

select *
  from yourtable
 where hour(yourfield)*100+minute(yourfield)=0005
;
3

select ... from ... where cast([answer] as time) = '00:05'

4

Is there a Sar-gable solution

CREATE TABLE #t
   ( Dt datetime
   , MinuteDt AS datepart(MINUTE, Dt) PERSISTED
   , PRIMARY KEY(MinuteDt, Dt)
   );
GO

INSERT #t ( Dt)
SELECT  Cast(DateAdd(mi, number, GetDate()) AS datetime)
FROM master.dbo.spt_values sv
WHERE sv.type='P'
AND sv.number BETWEEN 0 AND 1000;

SELECT t.Dt
     , t.MinuteDt 
FROM #t t
ORDER BY t.Dt;

SELECT t.Dt
     , t.MinuteDt
FROM #t t
WHERE t.MinuteDt = 5
ORDER BY t.Dt;

DROP TABLE #t;
GO