获取每个访客的第一条访问日志(获取网站的UV)-- 获取每个访客的第一条访问日志,初始化每个访客的第一个访问日志,计算UV CREATE TABLE access_log_first ( id BIGINT, ip STRING, province STRING, city STRING, isp STRING, access_time STRING, access_hour STRING, url STRING, status STRING, traffic STRING, referer STRING, ref_type STRING, c_in