我有一个SQL语句让我得到像这样的结果表......
categoryID | subCategoryID | categoryName
-------------------------------------------
1 | 2 | Animals & Pets
1 | 7 | Animals & Pets
1 | 10 | Animals & Pets
1 | 11 | Animals & Pets
4 | 0 | Books & Magazines
4 | 0 | Books & Magazines
4 | 0 | Books & Magazines
4 | 0 | Books & Magazines
4 | 31 | Books & Magazines
4 | 32 | Books & Magazines
4 | 33 | Books & Magazines
5 | 0 | Chemist
6 | 0 | Cloths & Accessories
6 | 0 | Cloths & Accessories
6 | 656 | Cloths & Accessories
7 | 0 | Collectables
7 | 0 | Collectables
7 | 0 | Collectables
8 | 0 | Computer
8 | 0 | Computer
8 | 0 | Computer
8 | 0 | Computer
8 | 0 | Computer
8 | 0 | Computer
8 | 56 | Computer
8 | 60 | Computer
8 | 61 | Computer
我现在只希望获得subCategoryID列中至少有4个不同ID的行，这些ID共享相同的categoryID，然后按categoryID对它们进行分组。例如，将上表转换为......
categoryID | subCategoryID | categoryName
-------------------------------------------
1 | 2 | Animals & Pets
4 | 0 | Books & Magazines
8 | 0 | Computer
到目前为止我的SQL是..
SELECT
listing.categoryID,
listing.subCategoryID,
categoryName
FROM listing
LEFT JOIN productInfo USING (listingID)
LEFT JOIN sectionCategory USING (categoryID)
WHERE listing.categoryID > 0
AND listing.listingStatus = 'A'
AND listing.pauseReason = 'A'
AND productInfo.quantity > 0
ORDER BY categoryID, subCategoryID
我尝试过使用...
SELECT
listing.categoryID,
categoryName
FROM listing
LEFT JOIN productInfo USING (listingID)
LEFT JOIN sectionCategory USING (categoryID)
WHERE listing.categoryID > 0
AND listing.listingStatus = 'A'
AND listing.pauseReason = 'A'
AND productInfo.quantity > 0
GROUP BY listing.categoryID
HAVING count(*) >= 4
ORDER BY RAND()
LIMIT 6
但它似乎只删除了列表数少于4的类别。任何想法？
答案 0 :(得分：1)
使用Having子句过滤具有至少4个不同categoryID的{{1}}。试试这个。
subCategoryID但我不确定你select categoryID , categoryName
from yourtable
group by categoryID , categoryName
having count(distinct subCategoryID)>= 4
的预期输出。
如果您希望至少每categoryID=4 subCategoryID category可能不是distinct，那么请使用此功能。
select categoryID , categoryName
from yourtable
group by categoryID , categoryName
having count(subCategoryID)>= 4
答案 1 :(得分：0)
如何加入临时表？
DROP TEMPORARY TABLE IF EXISTS categoryIDs;
CREATE TEMPORARY TABLE IF NOT EXISTS categoryIDs as(
select t.categoryID from
(select categoryID from table where distinct(categoryID) >=4 group by categoryID)t );