1
我想從左連接中得到一個表的總數,其中有多個相同的ID。下面是我下面的例子 -左連接的SQL計數結果
表1:
+-------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| project_id | int(11) | NO | | NULL | |
| token | varchar(32) | NO | | NULL | |
| email | varchar(255) | NO | | NULL | |
| status | char(1) | NO | | 0 | |
| permissions | varchar(255) | YES | | NULL | |
| created | datetime | NO | | NULL | |
| modified | datetime | NO | | NULL | |
+-------------+--------------+------+-----+---------+----------------+
表2:
+------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(32) | NO | | NULL | |
| account_id | int(11) | NO | | NULL | |
| created | datetime | NO | | NULL | |
| modified | datetime | NO | | NULL | |
| active | tinyint(1) | YES | | 1 | |
+------------+-------------+------+-----+---------+----------------+
我到目前爲止這種說法 -
SELECT account_id, (SELECT COUNT(invitations.id)
FROM invitations WHERE invitations.project_id = projects.id) AS inv_count
FROM projects order by account_id;
而這裏的結果的樣本:
+------------+-----------+
| account_id | inv_count |
+------------+-----------+
| 1 | 0 |
| 2 | 2 |
| 2 | 0 |
| 3 | 4 |
| 3 | 0 |
| 3 | 4 |
| 3 | 0 |
| 4 | 6 |
| 4 | 3 |
| 4 | 3 |
| 4 | 5 |
| 4 | 3 |
| 4 | 9 |
| 5 | 6 |
| 5 | 0 |
| 5 | 4 |
| 5 | 2 |
| 5 | 2 |
我如何獲取account_id以顯示一次,並顯示inv_count的總和爲1行?所以,我應該看到 -
+------------+-----------+
| account_id | inv_count |
+------------+-----------+
| 1 | 0 |
| 2 | 2 |
| 3 | 8 |
驚人,工程。 fyi-不是一些研究誰不研究,等嘗試不同的事情幾個小時試圖得到它。再次感謝。你能解釋一下這裏發生了什麼嗎? – waffles 2013-05-02 22:17:28