SELECT *, Age= datediff(yy,cast(case when substring(PersonalId,,) ') /*若第7位不是'1'或'2'则表示是15位身份证编码规则*/ then substring(PersonalId,,) ,) end as datetime),getdate()) FROM Student WHERE datediff(yy,cast(case when substring(PersonalId,,) ') then substring(P…