Question

當我運行此查詢

WITH install_count_join_date AS (
    SELECT 
    date_trunc('month', join_date) AS date, 
    COUNT(*) AS "inscountjoin" 
    FROM 
    apps202_prod.search 
    WHERE 
    join_date >= '2016-06-01' 
    AND 
    app_id = 3 
    GROUP BY 
    date_trunc('month', join_date) 
), install_count AS (
    SELECT 
    DATE(original_timestamp) AS date, 
    COUNT(*) AS "inscount" 
    FROM 
    apps202_prod.search 
    WHERE 
    original_timestamp >= '2016-06-01' 
    AND 
    app_id = 3 
    GROUP BY 
    DATE(original_timestamp) 
) 

SELECT 
    date_trunc('month', mr.date) AS "money_revenue_date", 
    SUM(mr.amount) AS "amt", 
    ic.inscount AS "install_count" 
FROM 
    mysql_apps202_prod.apps202_prod_money_revenue mr 
    join install_count ic on date_trunc('month', ic.date) = date_trunc('month', mr.date) 
WHERE 
    date_trunc('month', mr.date) >= '2016-06-01' 
AND 
    mr.app_id = 3 

GROUP BY 
    date_trunc('month', mr.date) 

我得到這個錯誤：

column ic.inscount must appear in the GROUP BY clause or be used in an aggregate function

Answer 1

你必須改變你的select語句如下，因爲你有很多關於你正在處理的問題的反饋，如果你正在使用group，那麼你選擇除了group by之外的所有具有聚合函數的列。在你的情況ic.inscount既不分組也不使用任何聚合函數，所以請根據您的要求使用下面的一個。

SELECT 
    date_trunc('month', mr.date) AS "money_revenue_date", 
    SUM(mr.amount) AS "amt", 
    ic.inscount AS "install_count" 
FROM mysql_apps202_prod.apps202_prod_money_revenue mr 
join install_count_join_date ic on date_trunc('month', ic.date) = date_trunc('month', mr.date) 
WHERE date_trunc('month', mr.date) >= '2016-06-01' 
    AND mr.app_id = 3 
GROUP BY date_trunc('month', mr.date), ic.inscount 

OR

SELECT 
    date_trunc('month', mr.date) AS "money_revenue_date", 
    SUM(mr.amount) AS "amt", 
    MAX(ic.inscount) AS "install_count" --Any Addregate Function 
FROM mysql_apps202_prod.apps202_prod_money_revenue mr 
join install_count_join_date ic on date_trunc('month', ic.date) = date_trunc('month', mr.date) 
WHERE date_trunc('month', mr.date) >= '2016-06-01' 
    AND mr.app_id = 3 
GROUP BY date_trunc('month', mr.date)