关于Mysql的查询问题,问题不好描述，看图片吧

Question

Answer 1

SELECT
count(a.id) num,
a.id,
a. NAME,
GROUP_CONCAT(b.tag)
FROM
table_A a
JOIN table_AB ab ON a.id = ab.a_id
JOIN (
SELECT
bb.id,
bb.tag
FROM
table_B bb
WHERE
bb.id IN (2, 3)
) b ON ab.b_id = b.id
GROUP BY
a.id
HAVING
num = 2