sql中mod()函数取余数的用法

select mod(3,2) from dual

UPDATE table_name SET 
SEX = (CASE WHEN mod(identifynumber[17],2) = '1' THEN '1' ELSE  '2' end) 
WHERE condition;

update table1  set 
sex = (select sex 
         from table2  
        where table2.t_id = table1.t_id 
          and table2.t_no = table1.t_no),
birthday = (select substr(identifynumber,7,8) 
              from table2         
             where table2.t_id = table1.t_id 
	           and table2.t_no = table1.t_no),
age = (select year(today) from dual) - ( select year( substr(identifynumber,7,8) ) 
                                           from table2 
                                          where table2.t_id = table1.t_id
                                            and table2.t_no = table1.t_no)
where t_id = '';

mysql> SELECT MOD(63,8),MOD(120,10),MOD(15.5,3);
+-----------+-------------+-------------+
| MOD(63,8) | MOD(120,10) | MOD(15.5,3) |
+-----------+-------------+-------------+
| 7 | 0 | 0.5 |
+-----------+-------------+-------------+
1 row in set (0.03 sec)