fix

server-db/src/main/java/cn/exploring/engine/server/db/dao/SpecialSqlMapper.java

@@ -230,12 +230,13 @@ public interface SpecialSqlMapper {
                           @Param("classId") Integer classId, @Param("startTime") String startTime, @Param("endTime") String endTime,
                           @Param("page") Integer page, @Param("limit") Integer limit, @Param("sort") String sort, @Param("order") String order);
 
+
     /**
      * 随机选择一个的学生
      * @param classId
      * @return
      */
-    @Select("SELECT * FROM (SELECT * FROM student_info WHERE deleted = FALSE AND class_id = ${classId})  a1 LEFT JOIN ( SELECT (RAND()  * max(id) ) as nid  FROM  student_info WHERE deleted = FALSE AND class_id = ${classId}) a2 ON a1.id > a2.nid LIMIT 1")
+    @Select("SELECT * FROM student_info WHERE deleted = FALSE AND class_id = ${classId} ORDER BY RAND() LIMIT 1")
     Map<String, Object> selectRandomStudentInfo(@Param("classId") Integer classId);
 
     @Select("<script> " +