src/main/kotlin/roomescape/schedule/business/ScheduleService.kt

@@ -30,8 +30,7 @@ class ScheduleService(
     fun findThemesByDate(date: LocalDate): AvailableThemeIdListResponse {
         log.info { "[ScheduleService.findThemesByDate] 동일한 날짜의 모든 테마 조회: date=$date" }
 
-        return scheduleRepository.findAllByDate(date)
+        return AvailableThemeIdListResponse(scheduleRepository.findAllUniqueThemeIdByDate(date))
-            .toThemeIdListResponse()
             .also {
                 log.info { "[ScheduleService.findThemesByDate] date=${date} 인 ${it.themeIds.size}개 테마 조회 완료" }
             }
@@ -54,8 +53,8 @@ class ScheduleService(
 
         val schedule: ScheduleEntity = findOrThrow(id)
 
-        val createdBy = memberService.findById(schedule.createdBy).name
+        val createdBy = memberService.findSummaryById(schedule.createdBy).name
-        val updatedBy = memberService.findById(schedule.updatedBy).name
+        val updatedBy = memberService.findSummaryById(schedule.updatedBy).name
 
         return schedule.toDetailRetrieveResponse(createdBy, updatedBy)
             .also {
@@ -63,6 +62,16 @@ class ScheduleService(
             }
     }
 
+    @Transactional(readOnly = true)
+    fun findSummaryById(id: Long): ScheduleSummaryResponse {
+        log.info { "[ScheduleService.findDateTimeById] 일정 개요 조회 시작 : id=$id" }
+
+        return findOrThrow(id).toSummaryResponse()
+            .also {
+                log.info { "[ScheduleService.findDateTimeById] 일정 개요 조회 완료: id=$id" }
+            }
+    }
+
     @Transactional
     fun createSchedule(request: ScheduleCreateRequest): ScheduleCreateResponse {
         log.info { "[ScheduleService.createSchedule] 일정 생성 시작: date=${request.date}, time=${request.time}, themeId=${request.themeId}" }

src/main/kotlin/roomescape/schedule/infrastructure/persistence/ScheduleRepository.kt

@@ -1,6 +1,7 @@
 package roomescape.schedule.infrastructure.persistence
 
 import org.springframework.data.jpa.repository.JpaRepository
+import org.springframework.data.jpa.repository.Query
 import java.time.LocalDate
 import java.time.LocalTime
 
@@ -11,4 +12,11 @@ interface ScheduleRepository : JpaRepository<ScheduleEntity, Long> {
     fun findAllByDateAndThemeId(date: LocalDate, themeId: Long): List<ScheduleEntity>
 
     fun existsByDateAndThemeIdAndTime(date: LocalDate, themeId: Long, time: LocalTime): Boolean
+
+    @Query("""
+        SELECT DISTINCT s.themeId
+        FROM ScheduleEntity s
+        WHERE s.date = :date 
+    """)
+    fun findAllUniqueThemeIdByDate(date: LocalDate): List<Long>
 }

src/main/kotlin/roomescape/schedule/web/ScheduleDto.kt

@@ -66,3 +66,15 @@ fun ScheduleEntity.toDetailRetrieveResponse(createdBy: String, updatedBy: String
     updatedAt = this.updatedAt,
     updatedBy = updatedBy
 )
+
+data class ScheduleSummaryResponse(
+    val date: LocalDate,
+    val time: LocalTime,
+    val themeId: Long
+)
+
+fun ScheduleEntity.toSummaryResponse() = ScheduleSummaryResponse(
+    date = this.date,
+    time = this.time,
+    themeId = this.themeId
+)