僅在本月而非sql之前購買的客戶

Question

我有購買記錄的列表，需要了解當月購買的總用戶，但過去幾個月從未購買過的用戶date_buy =購買日期

$hoy = date("Y-m-d");
$mesActual = date("Y-m-01");

SELECT count(DISTINCT(id_user)) 
        FROM transaction
        where date_buy BETWEEN '$mesActual' and '$hoy'
        AND date_buy >(select min(date_buy) FROM transaction)

謝謝

Answer 1

可能的方法是

 SELECT count(DISTINCT(id_user)) 
 FROM transaction t1
 WHERE date_buy BETWEEN '$mesActual' and '$hoy'
    AND NOT EXISTS (SELECT 1 FROM transaction t2 WHERE t2.id_user = t1.id_user AND t2.date_buy < '$mesActual')

Answer 2

找出您在日期之前購買的用戶，然后限制其id_users'

    SELECT count(DISTINCT(id_user)) 
    FROM transaction
    where date_buy BETWEEN '$mesActual' and '$hoy'
    AND id_user NOT IN (select id_user FROM transaction where date_buy < '$mesActual')