我想要顯示像這樣的數據我在哪裏GROUP
上DATE
:MySql的多列從單列表選擇與分組
Date Star1 Star2 Star3 Star4 Star5
2012-10-25 null null null 1 1
我目前的表有三(3)列,顯示:
ID DATE RATING
5 2012-10-25 4
6 2012-10-25 5
我使用此查詢來嘗試實現上述數據:
SELECT
DATE,
CASE
WHEN RATING = 1 THEN 1
ELSE NULL
END AS STAR1,
CASE
WHEN RATING = 2 THEN 1
ELSE NULL
END AS STAR2,
CASE
WHEN RATING = 3 THEN 1
ELSE NULL
END AS STAR3,
CASE
WHEN RATING = 4 THEN 1
ELSE NULL
END AS STAR4,
CASE
WHEN RATING = 5 THEN 1
ELSE NULL
END AS STAR5
FROM
table1
WHERE
DATE = '2012-10-25'
GROUP BY DATE
ORDER BY DATE
這隻能吐出一個等級壽:
Date Star1 Star2 Star3 Star4 Star5
2012-10-25 null null null null 1
它像它不是在日期分組,我怎麼能做到這一點?
這工作謝謝你! – ToddN
太棒了!很高興我能幫上忙。 – MikeB