MYSQL帮助，如何统计结果

Question

运行这个sql：

SELECT
    user_id,
    base_item
FROM
    items
WHERE
    base_item = "202"

给了我这个http://prntscr.com/9gwwxq 但是，如何扩展MYSQL查询以累计user_id具有的202个base_items。例如user_id 41有6.

Answer 1

这应该为每个用户ID提供“202”base_items的数量：

SELECT
    user_id,
    COUNT(*)
FROM
    items
WHERE
    base_item = "202"
GROUP BY user_id

Answer 2

尝试使用类似base_item的count

SELECT
    user_id, 
    base_item, count(*) as user_no
FROM
    items
WHERE
    base_item = "202" 
GROUP BY user_id

Answer 3

试一试：

SELECT
    user_id,
    count(base_item) as c
FROM
    items
WHERE
    base_item = "202"
group by
    user_id