要根据身份证号算年龄
语句:
insert into memberinfo(age)
select
(substring(now(),1,4)-substring(creditcard,7,4))-(substring(creditcard,11,4)-date_format(now(),'%m%d')>0)
from memberinfo
运行以后没有报错
insert into memberinfo(age)
select
(substring(now(),1,4)-substring(creditcard,7,4))-(substring(creditcard,11,4)-date_format(now(),'%m%d')>0)
from memberinfo
> Affected rows: 8388608****
> 时间: 102.076s
****
查询年龄以后,只有一部分是有数字的,其他都为空
请问是什么原因,该怎么办?