diff --git a/src/main/java/com/sqx/modules/course/service/impl/CourseDetailsServiceImpl.java b/src/main/java/com/sqx/modules/course/service/impl/CourseDetailsServiceImpl.java
index 29d4dbe7..8a8e14f0 100644
--- a/src/main/java/com/sqx/modules/course/service/impl/CourseDetailsServiceImpl.java
+++ b/src/main/java/com/sqx/modules/course/service/impl/CourseDetailsServiceImpl.java
@@ -1,5 +1,6 @@
 package com.sqx.modules.course.service.impl;
 
+import cn.hutool.core.lang.Validator;
 import cn.hutool.core.util.StrUtil;
 import com.alibaba.fastjson.JSONObject;
 import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
@@ -9,6 +10,7 @@ import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
 import com.baomidou.mybatisplus.core.toolkit.Wrappers;
 import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
+import com.sqx.common.exception.SqxException;
 import com.sqx.common.utils.DateUtils;
 import com.sqx.common.utils.PageUtils;
 import com.sqx.common.utils.Result;
@@ -238,6 +240,9 @@ public class CourseDetailsServiceImpl extends ServiceImpl<CourseDetailsDao, Cour
                 userId = Long.parseLong(claims.getSubject());
             }
         }
+        if(!Validator.isNumber(randomNum)){
+            throw new SqxException("随机码必须是数字");
+        };
         IPage<CourseDetails> courseDetailsIPage = baseMapper.selectCourseDetailsList(new Page<>(page, limit), randomNum, wxShow, dyShow);
 
         if (userId != null) {
diff --git a/src/main/resources/mapper/course/CourseDetailsDao.xml b/src/main/resources/mapper/course/CourseDetailsDao.xml
index 558bdb5e..6a4c05ac 100644
--- a/src/main/resources/mapper/course/CourseDetailsDao.xml
+++ b/src/main/resources/mapper/course/CourseDetailsDao.xml
@@ -57,7 +57,7 @@
         <if test='null != dyShow and dyShow==2'>
             and (c.dy_show = #{dyShow} or c.dy_show is null)
         </if>
-        order by SUBSTR(uid, #{randomNum}, 6)
+        order by SUBSTR(uid, ${randomNum}, 6)
     </select>
 
 </mapper>