Removing duplicates
Let's dig a little bit deeper into the database. You want to find out which composers have written a song that is sold by eSymphony.
Since composers can write multiple songs, your results will probably include many duplicate values. If you want to select all unique values from a column, you can use the DISTINCT keyword.
Deze oefening maakt deel uit van de cursus
Introduction to Oracle SQL
Praktische interactieve oefening
Probeer deze oefening eens door deze voorbeeldcode in te vullen.
-- Select the composers from the track table
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