Reigning weightlifting champions
A reigning champion is a champion who's won both the previous and current years' competitions. To determine if a champion is reigning, the previous and current years' results need to be in the same row, in two different columns.
Deze oefening maakt deel uit van de cursus
PostgreSQL Summary Stats and Window Functions
Praktische interactieve oefening
Probeer deze oefening eens door deze voorbeeldcode in te vullen.
SELECT
-- Return each year's champions' countries
___,
___ AS champion
FROM Summer_Medals
WHERE
Discipline = 'Weightlifting' AND
Event = '69KG' AND
Gender = 'Men' AND
Medal = ___;