选择 COUNT 与三个表 - mysql
问题描述：
我正在尝试使用三个表和一个查询(使用 WHERE 条件)选择 COUNT.
I am trying to select the COUNT with three tables with one single query (with WHERE conditions).
这是我无法正常工作的代码.
SELECT t1.count(id) AS car_model_count,t2.count(id) AS list_item_count,t3.count(id)
FROM `car_model` AS t1
INNER JOIN `list_item` AS t2
INNER JOIN `part_item` AS t3
WHERE t1.user_id=3;
答
Possible by using Sub-Query OR UNION is possible to get the COUNT代码> 来自多个表.试试这个查询:
Possible by using Sub-Query OR UNION is possible to get the COUNT from multiple table.
Try this query :
SELECT
(SELECT count(*) FROM `car_model` WHERE user_id=3 ) AS car_model_count,
(SELECT COUNT(*) FROM `list_item` WHERE user_id=3) AS list_item_count,
(SELECT count(*) FROM `part_item` WHERE user_id=3) AS part_item_count;