改进下面的mysql查询

Question

SELECT * FROM ***** 
WHERE ((first_appeared_on BETWEEN DATE_SUB( '2015-07-28' , INTERVAL 1 DAY ) AND '2015-07-28') 
      or (last_appeared_on BETWEEN DATE_SUB( '2015-07-28' , INTERVAL 1 DAY ) AND '2015-07-28'))

在上面的查询中，我不想一次又一次地输入日期（2015-07-28）我可以使用变量并为该变量赋值吗

day ='2015-07-28';

SELECT * FROM ***** 
WHERE ((first_appeared_on BETWEEN DATE_SUB(day , INTERVAL 1 DAY ) AND day) 
      or (last_appeared_on BETWEEN DATE_SUB( day , INTERVAL 1 DAY ) AND day))

Answer 1

这可以在MySQL中使用user-defined variable：

完成

SET @day = '2015-07-28';

SELECT * FROM ***** 
WHERE ((first_appeared_on BETWEEN DATE_SUB( @day , INTERVAL 1 DAY ) AND @day) 
  or (last_appeared_on BETWEEN DATE_SUB( @day , INTERVAL 1 DAY ) AND @day));