[英]Select Categories and count the Ads inside
我要查詢一個選擇類別名稱並計算每個類別中活動廣告的最大數量的查詢,我已經這樣做了:
SELECT
cat.cat_id,
cat.cat_desc,
COUNT(ad_id) AS cat_total_ads
FROM
tab_categories AS cat LEFT JOIN
tab_ads AS ads ON ads.cat_id = cat.cat_id
WHERE
cat_active = @cat_active AND
cat_deleted = @cat_deleted
GROUP BY
cat_desc, cat.cat_id
該查詢也在計算無效廣告。 如何將無效廣告的值設為0?
SUM(CASE .....然后1 else 0 end)作為colName應該為你做!
嘗試此操作,我沒有要重新創建的表以進行測試,但是此操作或類似操作應該起作用。
select
cat.cat_id,
cat.cat_desc,
count(ad_id) as Total,
sum(case when ad_id= 0 then 1 else 0 end) as 'ad_id'
from
tab_categoriesAS cat LEFT JOIN
tab_ads AS ads ON ads.cat_id = cat.cat_id
WHERE
cat_active = @cat_active AND
cat_deleted = @cat_deleted
GROUP BY
cat_desc, cat.cat_id
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.