pre assign rooms before checkin

src/main/kotlin/com/android/trisolarisserver/repo/RoomStayRepo.kt

@@ -47,4 +47,19 @@ interface RoomStayRepo : JpaRepository<RoomStay, UUID> {
         @Param("propertyId") propertyId: UUID,
         @Param("roomIds") roomIds: List<UUID>
     ): List<UUID>
+
+    @Query("""
+        select case when count(rs) > 0 then true else false end
+        from RoomStay rs
+        where rs.property.id = :propertyId
+          and rs.room.id = :roomId
+          and rs.fromAt < :toAt
+          and (rs.toAt is null or rs.toAt > :fromAt)
+    """)
+    fun existsOverlap(
+        @Param("propertyId") propertyId: UUID,
+        @Param("roomId") roomId: UUID,
+        @Param("fromAt") fromAt: java.time.OffsetDateTime,
+        @Param("toAt") toAt: java.time.OffsetDateTime
+    ): Boolean
 }