select * from if($personname和!$fname和!$surname)然后select * from user where name='$personname',if($personname和$fname和!$surname)然后select * from user where name='$personname‘和fname=' $fname ',如果($personname和!$fname和$surname)然后select * from user where name='$personname’和surname=
如果满足某一条件,如何更改列及其列名的输出值?假设我有表A,它有3列id,问候语,姓名,姓氏,性别select * from Aselectsalutation to Mr. else, set salutation to Ms. but then change the salutation into a