从一个SQL查询计算不同的数据

Question

I want to get the same results in SQL 2 as in SQL 1 but somehow that SQL query only count the total amount of data for every date, based on the WHERE .

SQL 1 (displays the right amount of data for each day)

SELECT DATE(datetime_logged) AS date,
COUNT(data_status) AS status_a

FROM activity
WHERE id_user = '1'
AND DATE(datetime_logged) != CURDATE()
AND data_status = 'online'
GROUP BY DATE(datetime_logged)
ORDER BY DATE(datetime_logged) DESC
LIMIT 40

SQL 2 (displays the wrong amount of data for each day)

SELECT DATE(datetime_logged) AS date,
(SELECT COUNT(data_status) 
         FROM activity 
         WHERE id_user = '1' 
         AND DATE(datetime_logged) != CURDATE() 
         AND data_status = 'online') AS status_a

FROM activity
GROUP BY DATE(datetime_logged)
ORDER BY DATE(datetime_logged) DESC
LIMIT 40

The table

CREATE TABLE IF NOT EXISTS `activity` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `id_user` int(11) NOT NULL,
  `id_channel` varchar(50) NOT NULL,
  `id_game` int(11) NOT NULL,
  `data_muted_server` tinyint(4) NOT NULL,
  `data_muted_self` tinyint(4) NOT NULL,
  `data_deafen_server` tinyint(4) NOT NULL,
  `data_deafen_self` tinyint(4) NOT NULL,
  `data_suppressed` tinyint(4) NOT NULL,
  `data_status` varchar(10) NOT NULL,
  `data_game` text,
  `datetime_logged` datetime NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`),
  KEY `index_datelog` (`datetime_logged`)
)

How can I accomplish this?

Answer 1

If I understand you correctly, I think you just need to tie the correlated subquery to the main query with:

AND a.datetime_logged=sub.datetime_logged

Example:

SELECT DATE(a.datetime_logged) AS date,
(SELECT COUNT(sub.data_status) 
         FROM activity sub
         WHERE sub.id_user = '1' 
         AND DATE(sub.datetime_logged) != CURDATE() 
         AND sub.data_status = 'online'
         AND a.datetime_logged=sub.datetime_logged) AS status_a

FROM activity a
GROUP BY DATE(a.datetime_logged)
ORDER BY DATE(a.datetime_logged) DESC
LIMIT 40