生日提前天数查询

SELECT a.* FROM   
(
SELECT t.name,t.birthday,CASE WHEN t.b>0 THEN t.b ELSE t.a END days
 FROM (  
   SELECT NAME,  
          birthday ,
          DATEDIFF(CONCAT(DATE_FORMAT(NOW(),'%Y')+1,DATE_FORMAT(birthday,'-%m-%d')),NOW()) a,  
          DATEDIFF(CONCAT(DATE_FORMAT(NOW(),'%Y'),DATE_FORMAT(birthday,'-%m-%d')),NOW()) b  
FROM  tb_micro_member
 ) t
) a WHERE a.days BETWEEN 0 AND 40; 

　　

原文链接：http://www.2cto.com/database/201212/172932.html