Merge multiple rows into one column without duplicates

Question

I am working on a query that will collect data from a table and display the data for a report.

The data looks like this:

Player Score
001      10
001           


        

Answer 1

Previous accepted answer is superseded in SQL 2017 and up by STRING_AGG:

SELECT Player, STRING_AGG(Score,', ') FROM YourTable GROUP BY Player

No need to use awkward FOR XML syntax.

I ran this and the accepted answer side-by-side on 100K rows. Accepted answer took 90 seconds, the STRING_AGG version takes less than 1 second.