結合這些mySQL查詢

Question

我需要結合這些查詢，所以我回來了一個月，一個新的總數，並返回總數（追蹤新的和返回的用戶）的列表。我目前有以下兩個查詢。第一個是新設備（檢測頻率），第二個設備返回。我想輸出結果，所以它是一個包含每個月的行的表格，然後是包含New和Returning data的兩列。

SELECT COUNT(DISTINCT (mac)) AS new, 
EXTRACT(MONTH FROM date_time) AS month 
FROM detected_devices 
WHERE client_id = 11 
AND venue_id = 1 
AND detection_frequency = 1 
GROUP BY month 

UNION ALL 

SELECT COUNT(DISTINCT (mac)) AS returning, 
EXTRACT(MONTH FROM date_time) AS month 
FROM detected_devices 
WHERE client_id = 11 
AND venue_id = 1 
AND detection_frequency > 1 
GROUP BY month 

我看了一下，但沒有找到任何關於如何用別名完成的信息。

Answer 1

這是怎麼回事？

SELECT t1.month, t1.new, t2.returning FROM (query 1) as t1, (query 2) as t2 where t1.month = t2.month; 

（或加入，取決於你喜歡什麼）。

Answer 2

這只是給你一個行有兩列，但應該給你的，你如何使用別名

SELECT 
A.new, 
B.returning 
FROM 
(SELECT COUNT(DISTINCT (mac)) AS new, 
EXTRACT(MONTH FROM date_time) AS month 
FROM detected_devices 
WHERE client_id = 11 
AND venue_id = 1 
AND detection_frequency = 1 
GROUP BY month) A, 
(SELECT COUNT(DISTINCT (mac)) AS returning, 
EXTRACT(MONTH FROM date_time) AS month 
FROM detected_devices 
WHERE client_id = 11 
AND venue_id = 1 
AND detection_frequency > 1 
GROUP BY month) B