🔧 added auction participant list

src/main/kotlin/com/toyProject7/karrot/auction/controller/AuctionController.kt

@@ -87,6 +87,18 @@ class AuctionController(
             }
         return ResponseEntity.ok(response)
     }
+
+    @GetMapping("/mypage/auctions")
+    fun getAuctions(
+        @AuthUser user: User,
+    ): ResponseEntity<List<AuctionItem>> {
+        val auctions: List<AuctionEntity> = auctionService.getAuctionsParticipatedByUserNickname(user.nickname)
+        val response: List<AuctionItem> =
+            auctions.map { auction ->
+                AuctionItem.fromAuction(Auction.fromEntity(auction))
+            }
+        return ResponseEntity.ok(response)
+    }
 }
 
 data class PostAuctionRequest(

src/main/kotlin/com/toyProject7/karrot/auction/persistence/AuctionEntity.kt

@@ -2,8 +2,10 @@ package com.toyProject7.karrot.auction.persistence
 
 import com.toyProject7.karrot.image.persistence.ImageUrlEntity
 import com.toyProject7.karrot.user.persistence.UserEntity
+import jakarta.persistence.CascadeType
 import jakarta.persistence.Column
 import jakarta.persistence.Entity
+import jakarta.persistence.FetchType
 import jakarta.persistence.GeneratedValue
 import jakarta.persistence.GenerationType
 import jakarta.persistence.Id
@@ -49,4 +51,6 @@ class AuctionEntity(
     var updatedAt: Instant,
     @Column(name = "view_count")
     var viewCount: Int,
+    @OneToMany(mappedBy = "auction", cascade = [CascadeType.ALL], orphanRemoval = true, fetch = FetchType.LAZY)
+    var participations: MutableList<AuctionParticipantEntity> = mutableListOf(),
 )

src/main/kotlin/com/toyProject7/karrot/auction/persistence/AuctionParticipantEntity.kt

@@ -0,0 +1,22 @@
+package com.toyProject7.karrot.auction.persistence
+
+import com.toyProject7.karrot.user.persistence.UserEntity
+import jakarta.persistence.Entity
+import jakarta.persistence.GeneratedValue
+import jakarta.persistence.GenerationType
+import jakarta.persistence.Id
+import jakarta.persistence.JoinColumn
+import jakarta.persistence.ManyToOne
+
+@Entity(name = "auction_participant")
+data class AuctionParticipantEntity(
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    val id: Long = 0,
+    @ManyToOne
+    @JoinColumn(name = "user_id", nullable = false)
+    val user: UserEntity,
+    @ManyToOne
+    @JoinColumn(name = "auction_id", nullable = false)
+    val auction: AuctionEntity,
+)

src/main/kotlin/com/toyProject7/karrot/auction/persistence/AuctionParticipantRepository.kt

@@ -0,0 +1,18 @@
+package com.toyProject7.karrot.auction.persistence
+
+import com.toyProject7.karrot.user.persistence.UserEntity
+import org.springframework.data.jpa.repository.JpaRepository
+import org.springframework.data.jpa.repository.Query
+import org.springframework.data.repository.query.Param
+
+interface AuctionParticipantRepository : JpaRepository<AuctionParticipantEntity, String> {
+    @Query("SELECT ap FROM auction_participant ap JOIN ap.user u WHERE u.nickname = :nickname")
+    fun findByUserNickname(
+        @Param("nickname") nickname: String,
+    ): List<AuctionParticipantEntity>
+
+    fun findByUserAndAuction(
+        user: UserEntity,
+        auction: AuctionEntity,
+    ): List<AuctionParticipantEntity>
+}

src/main/kotlin/com/toyProject7/karrot/auction/service/AuctionService.kt

@@ -15,6 +15,8 @@ import com.toyProject7.karrot.auction.controller.PostAuctionRequest
 import com.toyProject7.karrot.auction.persistence.AuctionEntity
 import com.toyProject7.karrot.auction.persistence.AuctionLikesEntity
 import com.toyProject7.karrot.auction.persistence.AuctionLikesRepository
+import com.toyProject7.karrot.auction.persistence.AuctionParticipantEntity
+import com.toyProject7.karrot.auction.persistence.AuctionParticipantRepository
 import com.toyProject7.karrot.auction.persistence.AuctionRepository
 import com.toyProject7.karrot.chatRoom.service.ChatRoomService
 import com.toyProject7.karrot.image.persistence.ImageUrlEntity
@@ -36,6 +38,7 @@ class AuctionService(
     @Lazy private val imageService: ImageService,
     private val articleRepository: ArticleRepository,
     private val chatRoomService: ChatRoomService,
+    private val participantRepository: AuctionParticipantRepository,
 ) {
     @Transactional
     fun updatePrice(auctionMessage: AuctionMessage): AuctionMessage {
@@ -53,6 +56,20 @@ class AuctionService(
 
         auctionEntity.currentPrice = auctionMessage.price
         auctionEntity.bidder = bidder
+
+        val existingParticipant = participantRepository.findByUserAndAuction(bidder, auctionEntity)
+        if (existingParticipant != null) {
+            throw IllegalStateException("User is already participating in this auction")
+        }
+
+        val participation =
+            AuctionParticipantEntity(
+                user = bidder,
+                auction = auctionEntity,
+            )
+
+        participantRepository.save(participation)
+
         if (ChronoUnit.SECONDS.between(Instant.now(), auctionEntity.endTime) <= 60) {
             auctionEntity.endTime = Instant.now().plus(1, ChronoUnit.MINUTES)
         }
@@ -245,4 +262,9 @@ class AuctionService(
             )
         }
     }
+
+    fun getAuctionsParticipatedByUserNickname(nickname: String): List<AuctionEntity> {
+        return participantRepository.findByUserNickname(nickname)
+            .map { it.auction }
+    }
 }

src/main/kotlin/com/toyProject7/karrot/user/persistence/UserEntity.kt

@@ -1,15 +1,19 @@
 package com.toyProject7.karrot.user.persistence
 
+import com.toyProject7.karrot.auction.persistence.AuctionParticipantEntity
 import com.toyProject7.karrot.image.persistence.ImageUrlEntity
+import jakarta.persistence.CascadeType
 import jakarta.persistence.Column
 import jakarta.persistence.DiscriminatorColumn
 import jakarta.persistence.Entity
+import jakarta.persistence.FetchType
 import jakarta.persistence.GeneratedValue
 import jakarta.persistence.GenerationType
 import jakarta.persistence.Id
 import jakarta.persistence.Inheritance
 import jakarta.persistence.InheritanceType
 import jakarta.persistence.JoinColumn
+import jakarta.persistence.OneToMany
 import jakarta.persistence.OneToOne
 import jakarta.persistence.Table
 import java.time.Instant
@@ -35,4 +39,6 @@ class UserEntity(
     var imageUrl: ImageUrlEntity? = null,
     @Column(name = "updated_at", nullable = false)
     var updatedAt: Instant,
+    @OneToMany(mappedBy = "user", cascade = [CascadeType.ALL], orphanRemoval = true, fetch = FetchType.LAZY)
+    val participations: MutableList<AuctionParticipantEntity> = mutableListOf(),
 )