獲得SQL

Question

記錄我有以下字段：

SELECT `sms_id`, 
     `u_id`, 
     `sender_id`, 
     `mobile_no`, 
     `message`, 
     `campaign_name`, 
     `status`, 
     `request_id`, 
     `route_id`, 
     `totalnumber`, 
     `msgcreadit`, 
     `date1`, 
     `deductbal`, 
     `submited` 
FROM `send_sms` 
WHERE 1 

我想選擇u_id其status ="pending"，但我根據[date1]日期字段想要最新的掛起狀態，我也想計數個人u_id s與status ="pending"。

我該怎麼辦？

Answer 1

在MySQL中，你可以這樣做：

SELECT s.* 
FROM `send_sms` s 
WHERE s.status = 'pending' AND 
     s.date1 = (SELECT MAX(s2.date1) FROM send_sms s2 WHERE s2.u_id = s.u_id and s2.status = 'pending'); 

Answer 2

只是另一種方法：

SELECT s.* 
FROM `send_sms` s 
LEFT JOIN `send_sms` s2 
ON s.date1 < s2.date1 
    AND s2.u_id = s.u_id 
    AND s2.status = 'pending' 
WHERE s.status = 'pending' 
    AND s2.status IS NULL