сделала кое-как как правильно делать не знаю

front/src/pages/Sessions.jsx

@@ -154,6 +154,7 @@ export default function Sessions() {
                         <th scope="col">Price</th>
                         <th scope="col">Cinema</th>
                         <th scope="col">Timestamp</th>
+                        <th scope="col">Capacity</th>
                         <th scope="col">MaxCount</th>
                         <th scope="col"></th>
                     </tr>

front/src/pages/components/OrderSessionItem.jsx

@@ -1,39 +1,17 @@
-import React, { useEffect, useState } from "react"
+import React from "react"
-import CinemaDto from "../models/CinemaDto";
-import Service from "../services/Service";
 import MyButton from "./MyButton";
 
 export default function OrderSessionItem(props) {
-    const [item, setItem] = useState(new CinemaDto())
-    const [load, setLoad] = useState(false)
-    const [date, setDate] = useState(new Date())
-
-    useEffect(() => {
-        Service.read("session/" + props.item.sessionId)
-            .then((data) => {
-                setItem(data)
-                setLoad(true)
-                setDate(new Date(data.timestamp).toLocaleString('RU-ru'))
-            })
-            .catch((error) => {
-                console.error('Error:', error);
-            });
-        return () => {
-            setLoad(false)
-        }
-    }, [])
-
     return (
         <>
-            {load ?
             <tr>
-                    <td>{item.id}</td>
+                <td>{props.item.session.id}</td>
-                    <td>{item.price}</td>
+                <td>{props.item.session.price}</td>
-                    <td>{item.cinema.name}</td>
+                <td>{props.item.session.cinema.name}</td>
-                    <td>{date}</td>
+                <td>{new Date(props.item.session.timestamp).toLocaleString('RU-ru')}</td>
                 <td>{props.item.count}</td>
                 <td><MyButton value={props} /></td>
-                </tr> : null}
+            </tr>
         </>
     )
 }

front/src/pages/components/SessionItem.jsx

@@ -10,6 +10,7 @@ export default function SessionItem(props) {
             <td>{props.item.price}</td>
             <td>{props.item.cinema.name}</td>
             <td>{date}</td>
+            <td>{props.item.maxCount - props.item.capacity}</td>
             <td>{props.item.maxCount}</td>
             <td><MyButton value={props} /></td>
         </tr>

src/main/java/com/labwork1/app/student/controller/OrderDto.java

@@ -23,7 +23,7 @@ public class OrderDto {
         if (order.getSessions() != null && order.getSessions().size() > 0)
             this.sessions = order.getSessions()
                     .stream()
-                    .map(x -> new OrderSessionDto(x.getId().getSessionId(),
+                    .map(x -> new OrderSessionDto(new SessionDto(x.getSession()),
                             x.getId().getOrderId(), x.getCount())).toList();
     }
 

src/main/java/com/labwork1/app/student/controller/OrderSessionDto.java

@@ -1,21 +1,21 @@
 package com.labwork1.app.student.controller;
 
 public class OrderSessionDto {
-    private Long sessionId;
+    private SessionDto session;
     private Long orderId;
     private Integer count;
 
     public OrderSessionDto() {
     }
 
-    public OrderSessionDto(Long sessionId, Long orderId, Integer count) {
+    public OrderSessionDto(SessionDto session, Long orderId, Integer count) {
-        this.sessionId = sessionId;
+        this.session = session;
         this.orderId = orderId;
         this.count = count;
     }
 
-    public Long getSessionId() {
+    public SessionDto getSession() {
-        return sessionId;
+        return session;
     }
 
     public Long getOrderId() {

src/main/java/com/labwork1/app/student/controller/SessionController.java

@@ -38,14 +38,16 @@ public class SessionController {
         SimpleDateFormat format = new SimpleDateFormat();
         format.applyPattern("yyyy-MM-dd-HH:ss");
         Date docDate = format.parse(timestamp.replace('T', '-'));
-        return new SessionDto(sessionService.addSession(Double.parseDouble(price),
+        return new SessionDto(sessionService.findSession(
-                new Timestamp(docDate.getTime()), cinemaId, capacity));
+                sessionService.addSession(Double.parseDouble(price),
+                new Timestamp(docDate.getTime()), cinemaId, capacity).getId()));
     }
 
     @PutMapping("/{id}")
     public SessionDto updateSession(@PathVariable Long id,
                                     @RequestParam("price") String price) {
-        return new SessionDto(sessionService.updateSession(id, Double.parseDouble(price)));
+        return new SessionDto(sessionService.findSession(sessionService
+                .updateSession(id, Double.parseDouble(price)).getId()));
     }
 
     @DeleteMapping("/{id}")

src/main/java/com/labwork1/app/student/controller/SessionDto.java

@@ -1,6 +1,5 @@
 package com.labwork1.app.student.controller;
 
-import com.labwork1.app.student.model.Cinema;
 import com.labwork1.app.student.model.Session;
 
 import java.sql.Timestamp;
@@ -10,7 +9,8 @@ public class SessionDto {
     private Double price;
     private Timestamp timestamp;
     private CinemaDto cinema;
-    private int capacity;
+    private Long capacity;
+
     private int maxCount;
 
     public SessionDto() {
@@ -20,6 +20,7 @@ public class SessionDto {
         this.id = session.getId();
         this.price = session.getPrice();
         this.timestamp = session.getTimestamp();
+        this.capacity = session.getCapacity();
         this.maxCount = session.getMaxCount();
         if (session.getCinema() != null) this.cinema = new CinemaDto(session.getCinema());
         else this.cinema = null;
@@ -29,14 +30,6 @@ public class SessionDto {
         return maxCount;
     }
 
-    public int getCapacity() {
-        return capacity;
-    }
-
-    public void setCapacity(int capacity) {
-        this.capacity = capacity;
-    }
-
     public long getId() {
         return id;
     }
@@ -49,6 +42,10 @@ public class SessionDto {
         return timestamp;
     }
 
+    public Long getCapacity() {
+        return capacity;
+    }
+
     public CinemaDto getCinema() {
         return cinema;
     }

src/main/java/com/labwork1/app/student/model/Session.java

@@ -27,6 +27,8 @@ public class Session {
     @NotNull(message = "maxCount can't be null or empty")
     @Column
     private Integer maxCount;
+    @Transient
+    private Long capacity;
 
     public Session() {
     }
@@ -41,6 +43,16 @@ public class Session {
         this.maxCount = maxCount;
     }
 
+    public Session(Session session, Long capacity) {
+        this.id = session.getId();
+        this.price = session.getPrice();
+        this.timestamp = session.getTimestamp();
+        this.orders = session.getOrders();
+        this.cinema = session.getCinema();
+        this.maxCount = session.getMaxCount();
+        this.capacity = capacity;
+    }
+
     public Cinema getCinema() {
         return cinema;
     }
@@ -83,6 +95,7 @@ public class Session {
                 "id=" + id +
                 ", price='" + price + '\'' +
                 ", timestamp='" + timestamp.toString() + '\'' +
+                ", capacity='" + capacity + '\'' +
                 ", maxCount='" + maxCount.toString() + '\'' +
                 ", cinema='" + cinema.toString() + '\'' +
                 '}';
@@ -96,6 +109,18 @@ public class Session {
         return price;
     }
 
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public void setOrders(List<OrderSession> orders) {
+        this.orders = orders;
+    }
+
+    public void setMaxCount(Integer maxCount) {
+        this.maxCount = maxCount;
+    }
+
     public void setPrice(Double price) {
         this.price = price;
     }
@@ -111,4 +136,12 @@ public class Session {
     public List<OrderSession> getOrders() {
         return orders;
     }
+
+    public Long getCapacity() {
+        return capacity;
+    }
+
+    public void setCapacity(Long capacity) {
+        this.capacity = capacity;
+    }
 }

src/main/java/com/labwork1/app/student/repository/SessionRepository.java

@@ -5,9 +5,19 @@ import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
+import java.util.List;
 import java.util.Optional;
 
 public interface SessionRepository extends JpaRepository<Session, Long> {
     @Query("Select sum(os.count) from OrderSession os where os.session.id = :sessionId")
     Optional<Integer> getCapacity(@Param("sessionId") Long sessionId);
+    @Query("Select new com.labwork1.app.student.model.Session(s, sum(os.count)) from Session s " +
+            "left join OrderSession os on s.id = os.session.id " +
+            "group by s")
+    List<Session> getSessionsWithCapacity();
+    @Query("Select new com.labwork1.app.student.model.Session(s, sum(os.count)) from Session s " +
+            "left join OrderSession os on s.id = os.session.id " +
+            "where s.id = :sessionId " +
+            "group by s")
+    Optional<Session> getSessionWithCapacity(@Param("sessionId") Long sessionId);
 }

src/main/java/com/labwork1/app/student/service/SessionService.java

@@ -8,9 +8,7 @@ import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 import java.sql.Timestamp;
-import java.util.Iterator;
 import java.util.List;
-import java.util.Optional;
 
 @Service
 public class SessionService {
@@ -35,13 +33,13 @@ public class SessionService {
 
     @Transactional(readOnly = true)
     public Session findSession(Long id) {
-        final Optional<Session> session = sessionRepository.findById(id);
+        return sessionRepository.getSessionWithCapacity(id)
-        return session.orElseThrow(() -> new SessionNotFoundException(id));
+                .orElseThrow(() -> new SessionNotFoundException(id));
     }
 
     @Transactional(readOnly = true)
     public List<Session> findAllSessions() {
-        return sessionRepository.findAll();
+        return sessionRepository.getSessionsWithCapacity();
     }
 
     @Transactional

src/test/java/com/labwork1/app/JpaCustomerTests.java

@@ -1,10 +1,7 @@
 package com.labwork1.app;
 
-import com.labwork1.app.student.model.Customer;
+import com.labwork1.app.student.model.*;
-import com.labwork1.app.student.model.Order;
-import com.labwork1.app.student.model.Session;
 import com.labwork1.app.student.service.*;
-import com.labwork1.app.student.model.Cinema;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
@@ -42,6 +39,7 @@ public class JpaCustomerTests {
                 new Timestamp(System.currentTimeMillis()), cinema1.getId(), 10);
         final Session session2 = sessionService.addSession( 200.0,
                 new Timestamp(System.currentTimeMillis()), cinema1.getId(), 10);
+
         // проверка 2 сеанса у 1 кино
         Assertions.assertEquals(cinemaService
                 .findCinema(cinema1.getId()).getSessions().size(), 2);
@@ -68,6 +66,9 @@ public class JpaCustomerTests {
                 .addOrder(customerService.findCustomer(customer2.getId()).getId());
         // у заказа 2 сеанса
         orderService.addSession(order2.getId(), session1.getId(), 2);
+
+        List<Session> result = sessionService.findAllSessions();
+
         Assertions.assertEquals(sessionService.getCapacity(session1.getId()), 2);
 
         orderService.addSession(order2.getId(), session2.getId(), 5);