fix: 디비 에러 수정 (#64)

* feat: 검색 기능 확장

* fix: nginx maxfilesize 변경

* feat: content type 반환

* feat: 사용자 정답 여부 반환

* fix: 데이터베이스 오류 해결

src/main/java/com/teamh/khumon/domain/Question.java

@@ -32,6 +32,8 @@ public class Question extends BaseEntity {
 //    private MyAnswer myAnswer;
 
     private String myAnswer;
+
+    @Column(columnDefinition = "TEXT")
     private String whatWrong;
     private Boolean isCorrect;
 

src/main/java/com/teamh/khumon/dto/QuestionInformation.java

@@ -11,7 +11,7 @@ public class QuestionInformation {
     private Long id;
     private String content;
     private String myAnswer;
-    private boolean isCorrect;
+    private Boolean isCorrect;
     private String whatWrong;
     private String answer;
 }

src/main/java/com/teamh/khumon/service/LearningMaterialService.java

@@ -105,7 +105,7 @@ public ResponseEntity<?> getLearningMaterial(Long id, Principal principal) {
                 .id(question.getId())
                 .content(question.getContent())
                 .myAnswer(question.getMyAnswer() == null ? null : question.getMyAnswer())
-                .isCorrect(question.getIsCorrect() != null && question.getIsCorrect())
+                .isCorrect(question.getIsCorrect() == null ? null :  question.getIsCorrect())
                 .whatWrong(question.getWhatWrong() == null ? null : question.getWhatWrong())
                 .answer(question.getAnswer().getAnswer())
                 .build()).toList();