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.
Este exercício faz parte do curso
Introduction to Oracle SQL
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
-- Select the composers from the track table
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