diff --git a/.idea/.gitignore b/.idea/.gitignore
new file mode 100644
index 0000000..13566b8
--- /dev/null
+++ b/.idea/.gitignore
@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
diff --git a/.idea/StudentManagement.iml b/.idea/StudentManagement.iml
new file mode 100644
index 0000000..d6ebd48
--- /dev/null
+++ b/.idea/StudentManagement.iml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>
\ No newline at end of file
diff --git a/.idea/compiler.xml b/.idea/compiler.xml
new file mode 100644
index 0000000..b589d56
--- /dev/null
+++ b/.idea/compiler.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CompilerConfiguration">
+    <bytecodeTargetLevel target="17" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
new file mode 100644
index 0000000..4c4db4a
--- /dev/null
+++ b/.idea/misc.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="MavenRunner">
+    <option name="jreName" value="17" />
+  </component>
+  <component name="ProjectRootManager" version="2" project-jdk-name="17" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/modules.xml b/.idea/modules.xml
new file mode 100644
index 0000000..59d3df4
--- /dev/null
+++ b/.idea/modules.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/StudentManagement.iml" filepath="$PROJECT_DIR$/.idea/StudentManagement.iml" />
+    </modules>
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..35eb1dd
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/code/src/dao/UserDao.java b/code/src/dao/UserDao.java
index d32ca0c..0224572 100644
--- a/code/src/dao/UserDao.java
+++ b/code/src/dao/UserDao.java
@@ -17,8 +17,8 @@ public boolean userIsExist(String username) {
 		Connection conn = DBUtils.getConnection();
 		String sql = "select * from user where username = ?";
 		try{
-			//获取PreparedStatement对象
-			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
+			//获取Statement对象
+			Statement ps = (Statement) conn.Statement(sql);
 			ps.setString(1, username);//给用户对象属性赋值
 			ResultSet rs = ps.executeQuery();
 			if (rs.next()) {
@@ -42,8 +42,8 @@ public User login(String username,String password) {
 		String sql = "select * from user where username = ? and password = ?;";
 		
 		try {
-			//获取PreparedStatement对象
-			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
+			//获取Statement对象
+			Statement ps = (Statement) conn.Statement(sql);
 			//对sql参数进行动态赋值
 			ps.setString(1, username);
 			ps.setString(2, password);
@@ -98,7 +98,7 @@ public String level(String username){
 		String sql = "select level from user where username = ?;";
 		String level = null; 
 		try {
-			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
+			Statement ps = (Statement) conn.Statement(sql);
 			ps.setString(1, username);
 			ResultSet rs = ps.executeQuery();
 			if(rs.next()){//存在该用户
@@ -121,7 +121,7 @@ public ArrayList<User> query_all_user() {
 		ArrayList<User> results = new ArrayList<User>();
 		
 		try {
-			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
+			Statement ps = (dStatement) conn.Statement(sql);
 			ResultSet rs = ps.executeQuery();
 
 			while(rs.next()){
@@ -148,7 +148,7 @@ public int insert_user(String username,String password,String level){
 		
 		int flag = 0;
 		try {
-			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
+			Statement ps = (Statement) conn.Statement(sql);
 			
 			ps.setString(1, username);
 			ps.setString(2, password);
@@ -169,7 +169,7 @@ public int delete_user(String username) {
 		
 		int flag = 0;
 		try {
-			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
+			Statement ps = (Statement) conn.Statement(sql);
 			ps.setString(1, username);
 			flag = ps.executeUpdate();
 			ps.close();
@@ -187,7 +187,7 @@ public int alter_user(String username,String after_username,String after_passwor
 		
 		int flag = 0;
 		try {
-			PreparedStatement ps = (PreparedStatement) conn.prepareStatement(sql);
+			Statement ps = (Statement) conn.Statement(sql);
 			ps.setString(1, after_username);
 			ps.setString(2, after_password);
 			ps.setString(3, after_level);