【修改】删除数据库判空

src/main/java/com/example/exam/exam/service/mysql/IMysqlLocalServiceImpl.java

@@ -1009,7 +1009,7 @@ public class IMysqlLocalServiceImpl implements IMysqlLocalService {
 
         try (Connection connstu = DriverManager.getConnection(stuDbUrl, user, password);
              Statement stmtstu = connstu.createStatement()) {
-
+            if (tNames!=null&&tNames.size()>0){
                 for (String tName : tNames) {
                     // 校验数据库名格式，防止 SQL 注入
                     if (!tName.matches("^[a-zA-Z0-9_]+$")) {
@@ -1029,7 +1029,7 @@ public class IMysqlLocalServiceImpl implements IMysqlLocalService {
                         }
                     }
                 }
-
+            }
         } catch (SQLException e) {
             e.printStackTrace();
             throw new RuntimeException("数据库操作失败", e);