diff --git a/demo6_src/com/system/dao/CourseDao.java b/demo6_src/com/system/dao/CourseDao.java
deleted file mode 100644
index 03c9026..0000000
--- a/demo6_src/com/system/dao/CourseDao.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package com.system.dao;
-
-import java.sql.SQLException;
-import java.util.List;
-
-import com.system.entity.Course;
-
-public interface CourseDao {
-	public Course selectByCno(int cno) throws SQLException;
-	public List<Course> courseRes() throws Exception;
-	public boolean insert(String cno, String cname, String ccredit, String ctime) throws SQLException;
-	public boolean delete(String cno) throws SQLException;
-	public Course select(String cno) throws SQLException;
-	public boolean update(String cno, String cname, String ccredit, String ctime) throws SQLException;
-}