sql喜欢搜索字符

Question

你好，我想在5个字符后搜索

(yyyy-mm-dd)
2000-02-01
2001-01-01
2001-01-05
2001-03-03

我想获得mm值

 select * from day , employee 
 where Employee.ID = Day.Employee and employee = "$_ID" 
and day.leaveday like "%$month%";

问题是，如果我使用%%（通配符）所有内容，如20001 - 03 - 03,2000-02-01，它将显示我如何获得价值mm？

有什么想法吗？在此先感谢您的帮助，如果之前有人问过，我真的很抱歉

Answer 1

我正在服用它，是一个日期，日期时间或时间戳列。如果不是因为你存储日期而首先制作一个。这也将防止出现诸如20001之类的无效日期。然后使用mysql extract function运行类似这样的东西

 select * from day , employee where Employee.ID = Day.Employee and employee = "$_ID" and extract(month from day.leaveday)=3

Answer 2

select * from day , employee 
 where Employee.ID = Day.Employee and employee = "$_ID" 
and MONTH(day.leaveday)="$month";