mysql - SQLzoo tutorial | GROUP BY and HAVING -

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i can't answer correctly following question in

show years in 3 prizes given physics.

i've written following script returns wrong.

select yr, count(subject) nobel subject = 'physics' group yr having count(subject) = 3

thank time

that query looks correct, can't sure without link sqlzoo page.

try 

select yr nobel subject = 'physics' group yr having count(subject) = 3

-- might finicky exact format of results returning. it's asking year.


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