Forespørgsel ikke fuldført - MYSQL

Det lyder som om du skal tilføje en samlet funktion:

SELECT CD_NO, purchase_date, Count(purchase_date) totalSalesFROM ArtistGROUP BY purchase_dateORDER BY CD_NO 

MySQL giver dig mulighed for at begrænse antallet af felter, som du GRUPPER EFTER så dette ovenfor er kun gruppering på purchase_date .

I andre RDBMS kan du bruge en underforespørgsel:

SELECT a1.CD_NO, a1.purchase_date, a2.TotalSalesByDateFROM Artist a1INNER JOIN( SELECT count(purchase_date) TotalSalesByDate, purchase_date FROM Artist GROUP BY purchase_date) a2 on a1.purchase_date=a2.purchase_BY_dateOR.CDDER /kode> 

SELECT a1.CD_NO, date_format(a1.purchase_date, '%Y-%m-%d') MostSalesFROM Artist a1INNER JOIN( SELECT count(purchase_date) TotalSalesByDate, purchase_date FROM Artist GROUP BY purchase_date) a2 on a1 .purchase_date=a2.purchase_dategroup by a1.CD_NO, a1.purchase_datehaving max(TotalSalesByDate) =(vælg max(Total) totalsalg fra ( SELECT cd_nr, purchase_date, Count(purchase_date) Total FROM Artist a1 GROUP BY cd_no) .cd_no =src.cd_no GROUP BY cd_no);