我在MySQL数据库中为表“Bookings”创建了一个Bookings类（Model类），该类中的所有数据成员都是根据数据库表设置的。
所有GET请求都有效，只有POST请求返回错误。
存储库接口：

package com.example.demo.bookings;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface BookingsRepository extends CrudRepository<Bookings, Integer>{

    Iterable<Bookings> findAllByBookingName(String name);

}

BookingsController类别：

package com.example.demo.bookings;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class BookingsController {
    
    @Autowired
    BookingsService bs;
    
    @RequestMapping("/bookings")
    public List<Bookings> getBookings(){
        return bs.getAllBookings();
    }
    
    @RequestMapping("/{name}/bookings")
    public List<Bookings> getBookings(@PathVariable String name){
        return bs.getBookingsByName(name);
    }
    
    @PostMapping("/bookings")
    public void addBookings(Bookings bookings) {
        bs.addBookings(bookings);
    }
}

预订POJO课程：

package com.example.demo.bookings;

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class Bookings {
    @Id
    int bookingId;
    String bookingName;
    int bookingPid;
    int passengers;
    int cost;
    
    public Bookings() {
        
    }

    public Bookings(int bookingId, String bookingName, int bookingPid, int passengers, int cost) {
        super();
        this.bookingId = bookingId;
        this.bookingName = bookingName;
        this.bookingPid = bookingPid;
        this.passengers = passengers;
        this.cost = cost;
    }

    public int getBookingId() {
        return bookingId;
    }

    public void setBookingId(int bookingId) {
        this.bookingId = bookingId;
    }

    public String getBookingName() {
        return bookingName;
    }

    public void setBookingName(String bookingName) {
        this.bookingName = bookingName;
    }

    public int getBookingPid() {
        return bookingPid;
    }

    public void setBookingPid(int bookingPid) {
        this.bookingPid = bookingPid;
    }

    public int getPassengers() {
        return passengers;
    }

    public void setPassengers(int passengers) {
        this.passengers = passengers;
    }

    public int getCost() {
        return cost;
    }

    public void setCost(int cost) {
        this.cost = cost;
    }
    
    
}

编辑二：
按照建议，我将名称中有'_'的列的模型类数据成员更改为camelcase。这帮助解决了我所面临的许多问题，但POST方法仍然返回错误。
尝试POST请求时出现的错误：

java.sql.SQLIntegrityConstraintViolationException: Column 'booking_name' cannot be null