Update free-courses-en.md (#4717)

free-courses-en.md

@@ -569,6 +569,7 @@
 
 ### SQL
 
+* [Introduction to Database Queries](https://www.edx.org/course/introduction-to-database-queries) - (edX New York University) - (Aspen Olmsted)
 * [SQL Tutorial](https://www.youtube.com/playlist?list=PL_RGaFnxSHWr_6xTfF2FrIw-NAOo3iWMy)
 * [SQL Tutorial - Full Database Course for Beginners](https://www.youtube.com/watch?v=HXV3zeQKqGY) - (Mike Dane) - (freeCodeCamp)