我记录访问者的ip地址并将其存储到mysql数据库中。如果访问者获得不同的IP,它也将更新记录。我使用以下代码进行更新,以下示例中的值仅用于测试。
insert into visiter_info values ('1344594088179','0','100.100.100.100','china','300x600','IOS','firefox','')
ON DUPLICATE KEY UPDATE
ip_address=concat(ip_address,'|','100.100.100.100'),
location=concat(location,'|','china'),
screen_res=concat(screen_res,'|','300x600'),
os=concat(os,'|','IOS'),
brower=concat(brower,'|','firefox')
它有效,但现在出现问题,如何检查数据库中是否有记录?像这样:访客再来,ip 100.100.100.100。 Mysql不知道有记录,它会重新记录。如何在插入之前检查是否包含子字符串?
答案 0 :(得分:0)
if not exists(select * from visiter_info where ip_address='100.100.100.100')
insert into visiter_info values ('1344594088179','0','100.100.100.100','china','300x600','IOS','firefox','')
ON DUPLICATE KEY UPDATE
ip_address=concat(ip_address,'|','100.100.100.100'),
location=concat(location,'|','china'),
screen_res=concat(screen_res,'|','300x600'),
os=concat(os,'|','IOS'),
brower=concat(brower,'|','firefox')