mysql 关联左表不存在数据 并 根据身份证计算查找大于65岁以上老人

---

//查找左边不存在数据,不能用 = ''

SELECT
    m.uid
FROM
    es_members m
LEFT JOIN es_user_self_care_assessment u ON m.uid =         u.user_id
  WHERE
u.user_id IS NULL  

//合并起来查找 
#(YEAR (NOW()) -  substring(m.idcard, 7, 4)) as n 计算出年龄

SELECT
    m.uid,(YEAR (NOW()) -  substring(m.idcard, 7, 4)) as n
FROM
    es_members m
LEFT JOIN es_user_self_care_assessment u ON m.uid = u.user_id
WHERE
  m.idcard >0 and
    u.user_id IS NULL HAVING n>65