T-SQL Convert multiple rows to comma separated String

The below query returns 17 unique reference numbers from 400+ rows

from DAY_943 where Unique_Ref = '00138AMCR2018-04-21'

Open in new window

I need to output this as a single comma separated string.
By googling I see methods using CTE and XML Path, but not having much luck
Can anyone give me a hand with this Please.

I am using Mangement Studio 2014
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

JDCamAuthor Commented:
I got it to work with this.
SELECT Distinct(Ref_num) + ', ' AS 'data()' 
where Unique_Ref = '00138AMCR2018-04-21'

Open in new window

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Query Syntax

From novice to tech pro — start learning today.