diff --git a/db/dbuml.db3 b/db/dbuml.db3
index 7b35501..35d5f65 100644
Binary files a/db/dbuml.db3 and b/db/dbuml.db3 differ
diff --git a/src/DML.java b/src/DML.java
index 8b55574..df5bcfe 100644
--- a/src/DML.java
+++ b/src/DML.java
@@ -3,9 +3,12 @@ import java.sql.*;
 import org.junit.Test;
 
 import java.sql.*;
+import java.time.LocalDateTime;
 
 import org.junit.Test;
 
+import java.util.Random;
+
 public class DML {
 
     // 使用相对路径
@@ -76,7 +79,7 @@ public class DML {
         } catch (SQLException e) {
             e.printStackTrace();
         }
-    }  //清空指定数据表数据
+    }  //清空指定数据表数
     @Test
     public void dropTable() {
         try (Connection conn = DriverManager.getConnection(URL);
@@ -211,4 +214,6 @@ public class DML {
             e.printStackTrace();
         }
     }
+
+
 }
\ No newline at end of file