MySQL GROUP BY 分组后加条件HAVING使用方法

-- 分组后再加条件 
-- 列子 获取角色下大于2的用户角色信息
SELECT A.id,A.`name`,COUNT(A.id) AS cun FROM ddos_roles AS A
LEFT JOIN ddos_users AS B ON A.id = B.roleid
GROUP BY A.id HAVING COUNT(A.id) >= 2-- GROUP BY 分组的字段 HAVING 您的条件