feat: return exam question score rates

src/main/java/com/sztzjy/linkCommerce/service/ExamService.java

@@ -425,10 +425,22 @@ public class ExamService {
                 bucket("良好", scores, total.multiply(new BigDecimal("0.80")), total.multiply(new BigDecimal("0.90"))),
                 bucket("及格", scores, pass, total.multiply(new BigDecimal("0.80"))),
                 bucket("不及格", scores, BigDecimal.ZERO, pass));
-        List<Map<String, Object>> hardest = jdbc.query("select q.id,q.stem,count(*) wrong_count from exam_attempt_answer a " +
-                        "join exam_attempt t on t.id=a.attempt_id join exam_question q on q.id=a.question_id where t.exam_id=? and t.attempt_status='SUBMITTED' and a.is_correct=0 " +
-                        (StringUtils.isBlank(classId) ? "" : "and t.teaching_class_id=? ") + "group by q.id,q.stem order by wrong_count desc limit 3",
-                (rs, n) -> map("id", rs.getLong("id"), "stem", rs.getString("stem"), "wrongCount", rs.getInt("wrong_count")),
+        String hardestSql = "select p.question_id id,p.stem,p.question_score, count(distinct t.id) student_count, " +
+                "sum(case when coalesce(a.awarded_score,0) < p.question_score then 1 else 0 end) wrong_count, " +
+                "coalesce(sum(coalesce(a.awarded_score,0)),0) earned_score " +
+                "from exam_assessment_question p join exam_attempt t on t.exam_id=p.exam_id and t.attempt_status='SUBMITTED' " +
+                "left join exam_attempt_answer a on a.attempt_id=t.id and a.question_id=p.question_id " +
+                "where p.exam_id=?" + (StringUtils.isBlank(classId) ? "" : " and t.teaching_class_id=? ") +
+                "group by p.question_id,p.stem,p.question_score " +
+                "order by (case when count(distinct t.id)=0 then 100 else coalesce(sum(coalesce(a.awarded_score,0)),0) * 100.0 / (count(distinct t.id) * p.question_score) end) asc, wrong_count desc limit 3";
+        List<Map<String, Object>> hardest = jdbc.query(hardestSql,
+                (rs, n) -> {
+                    int students = rs.getInt("student_count");
+                    BigDecimal maxScore = rs.getBigDecimal("question_score").multiply(BigDecimal.valueOf(students));
+                    BigDecimal earnedScore = rs.getBigDecimal("earned_score");
+                    BigDecimal scoreRate = maxScore.signum() == 0 ? BigDecimal.ZERO : earnedScore.multiply(new BigDecimal("100")).divide(maxScore, 2, BigDecimal.ROUND_HALF_UP);
+                    return map("id", rs.getLong("id"), "stem", rs.getString("stem"), "wrongCount", rs.getInt("wrong_count"), "scoreRate", scoreRate);
+                },
                 StringUtils.isBlank(classId) ? new Object[]{examId} : new Object[]{examId, classId});
         return map("examName", exam.get("name"), "expected", expected, "attended", scores.size(), "passed", passed,
                 "failed", scores.size() - passed, "highest", scores.stream().max(BigDecimal::compareTo).orElse(BigDecimal.ZERO),