fix: term 테이블의 is_current 필드에 UK 설정 (#650)

* fix: is_current 필드에 UK 설정

* test: UK 설정에 따른 테스트 코드 불일치성 해결

* chore: 스크립트 버전 수정

* refactor: 미사용 코드 제거

Author: whqtker

src/main/java/com/example/solidconnection/term/domain/Term.java

@@ -31,19 +31,11 @@ public class Term {
     @Column(length = 20)
     private String name;
 
-    @Column(name = "is_current", nullable = false)
-    private boolean isCurrent = false;
+    @Column(name = "is_current", unique = true)
+    private Boolean isCurrent;
 
     public Term(String name, boolean isCurrent) {
         this.name = name;
-        this.isCurrent = isCurrent;
-    }
-
-    public void setAsCurrent() {
-        this.isCurrent = true;
-    }
-
-    public void setAsNotCurrent() {
-        this.isCurrent = false;
+        this.isCurrent = isCurrent ? true : null;
     }
 }

src/main/resources/db/migration/V46__add_unique_constraint_to_term_is_current.sql

@@ -0,0 +1,9 @@
+ALTER TABLE term
+    MODIFY COLUMN is_current BOOLEAN NULL DEFAULT NULL;
+
+UPDATE term
+SET is_current = NULL
+WHERE is_current = FALSE;
+
+ALTER TABLE term
+    ADD CONSTRAINT uk_term_is_current UNIQUE (is_current);

src/test/java/com/example/solidconnection/mentor/service/MentorQueryServiceTest.java

@@ -60,7 +60,7 @@ class MentorQueryServiceTest {
 
     @BeforeEach
     void setUp() {
-        termFixture.현재_학기("2025-2");
+        termFixture.현재_학기("2025-1");
         university = universityFixture.그라츠_대학();
     }
 

src/test/java/com/example/solidconnection/siteuser/service/MyPageServiceTest.java

@@ -114,7 +114,7 @@ class MyPageServiceTest {
     @BeforeEach
     void setUp() {
         user = siteUserFixture.사용자();
-        term = termFixture.현재_학기("2025-2");
+        term = termFixture.현재_학기("2025-1");
         UnivApplyInfo 괌대학_A_지원_정보 = univApplyInfoFixture.괌대학_A_지원_정보(term.getId());
         괌대학_A_지원_정보_ID = 괌대학_A_지원_정보.getId();
         괌대학 = 괌대학_A_지원_정보.getUniversity();