我有我的MongoDB集合這樣一個JSON文件: 更新文件: {
"_id" : ObjectId("59da4aef8c5d757027a5a614"),
"input" : "hi",
"output" : "Hi. How can I help you?",
"intent" : "[{\"intent\":\"greeting\",\"confidence\":0.81540894
組 條件第一次出現的列值我有一個熊貓數據框如下: player condition num
A 0 1
A 1 2
A 1 3
B 0 1
B 0 2
B 1 3
B 0 4
我想補充一點,存儲num列,其中每player的最低值的列condition列是。 的結果,因此,應該是這樣的: player condition num numC
我有一個表格cast約有150萬行,有一個小表約有1000-2000行看。兩個表共享一個名爲movieId的列。我試圖運行此查詢: SELECT actorId, COUNT(actorId)
FROM cast t1
WHERE EXISTS (
SELECT userId
FROM watched t2
WHERE t1.movieId = t2.movieI
我有一個包含時間戳登錄的表的MySQL數據庫,我想獲得過去24小時每個小時的登錄次數。 起初,我嘗試了一些東西明顯: SELECT
timestamp AS Hour,
COUNT(*) AS Logins
FROM auth
WHERE
timestamp >= DATE_SUB(NOW(), INTERVAL 1 DAY)
GROUP BY HOUR(tim
與聯接涉及組select語句的集合函數我有兩個表具有以下屬性: t1 t2
source domain date rank domain date
--- --- --- --- --- ---
A google 2008-10-24 1 google 2007-10-20
A facebook 2010-05-17 1 google 200