from lot_user t WHERE t.user_landphone IS NOT NULL;
select CONCAT(t.user_landphone,‘,’,t.user_name,‘,’,t.user_sex,‘,’,t.user_birthday,‘,’,t.province)--concat函数,concat_ws函数用法功能一样但是写法不一样;
from lot_user t WHERE t.user_landphone IS NOT NULL;
select t.user_landphone (length函数截取字符长度位数)
from lot_user t WHERE t.user_landphone IS NOT NULL AND LENGTH(t.user_landphone)>10 AND t.user_landphone LIKE '1%';