SQL Server : converting varchar to INT

Question

I am stuck on converting a varchar column UserID to INT. I know, please don\'t ask why this UserID column was not created as

Answer 1

This is more for someone Searching for a result, than the original post-er. This worked for me...

declare @value varchar(max) = 'sad';
select sum(cast(iif(isnumeric(@value) = 1, @value, 0) as bigint));

returns 0

declare @value varchar(max) = '3';
select sum(cast(iif(isnumeric(@value) = 1, @value, 0) as bigint));

returns 3