How to correct an error in SELECT statement - sql-server

Question

I've coded on SQL Server 2014:
create table CriticalStop
(
SAP_ID int not null,
Affected_ID char(15) not null,
FnLoc_ID char(20) not null,
MalFn_date date,
MalFn_time time,
MalFnHour_dur float,
MalFnMajor char(15),
primary key(SAP_ID)
);
go
insert into CriticalStop(SAP_ID, Affected_ID, FnLoc_ID, MalFn_date, MalFn_time, MalFnHour_dur, MalFnMajor)
values (10045929, 'TN.211-HC1', 'TN.211-HC1', convert(date,'20190101'), convert(time,'18:29:00.290'), 3.52, 'Process')
They was okay. but when I used statement below, SQL Server 2014 raised an error
select
SAP_ID,
Affected_ID,
FnLoc_ID,
MalFn_date+3 as MalFn_delay,
MalFn_time,
MalFnHour_dur,
MalFnMajor
from
CriticalStop;
Error:
Msg 206, Level 16, State 2, Line 2314
Operand type clash: date is incompatible with int.
Line 2314 was pointing to SELECT statement above. I don't understand why this error happens on line MalFn_date+3 as MalFn_delay. I remove +3, the result is okay, but I need to change its date. How can I get it working with +3.

Answer 1

It says what the problem is right in the error message, date is incompatible with int. You're trying to add an integer to a date field.
MalFn_date+3 as MalFn_delay,
You need to convert the integer to a time range so that it can be added to the date. SQL has no idea what 3 represents; seconds, minutes, days?
You can use the DATEADD() function to do this in SQL Server. For example, if you wanted to add 3 days,
DATEADD(day, 3, MalFn_date)