如何使用外键发布新产品以添加具有category\u id、Angular和SpringBoot的产品

Question

我有两个实体产品和类别（多对一）关系。我想添加一个新产品，但总是失败。

控制台和邮递员中均出现错误：原因：{原因：{…}，消息：'无法执行语句'}消息：'无法执行语句；SQL[不适用]；约束[空]；嵌套异常为org.hibernate.exception.ConstraintViolationException：

任何帮助请！！

产品ts

export class Product {
  public id: number;
  public description;
  public name: string;
  public unitPrice: number;
  public materiaux: string;
  public categoryId:number;}

**ProductCategory.ts**

export class ProductCategory {
  public id:number;
  public categoryName:string;
}

catalogue.service.ts：发布方法

public postData(value)  {
    return this.httpClient.post(this.host+"products",value);
  }

新产品。组成部分ts

import { Component, OnInit } from '@angular/core';
import {CatalogueService} from "../services/catalogue.service";
import {Router} from "@angular/router";
import {Product} from "../model/product.model";

@Component({
  selector: 'app-new-product',
  templateUrl: './new-product.component.html',
  styleUrls: ['./new-product.component.css']
})
export class NewProductComponent implements OnInit {
  ProductCategories: any;
  products:any;
  size:number=5;
  currentPage:number=0
  totalPages:number=0
  pages:Array<number>;
  ProductCategory:any;

  private  currentProduct:any;
  constructor(private service:CatalogueService, private router:Router) { }

  ngOnInit() {
    this.onGetProducts();
    this.service.findAllCategory().subscribe(data =>{
      this.ProductCategories=data ;
    },error=>{
      console.log(error);
    })
  }
  saveProduct(value) {

    this.service.findCategory(value.category).subscribe(data=>{
      this.ProductCategory = data;
      console.log(data);
    });
    value = {
      "name": value.name,
      "quantity":value.quantity,
      "unitPrice":value.unitPrice,
      "materiaux":value.materiaux,
      "category": this.ProductCategory,

    }
    this.service.postData(value).subscribe(d =>{
      this.currentProduct =  d;
    return this.router.navigateByUrl("/new-product");
    });
  }
  }

新产品。html

<div class="card">
    <div class="card-body">
        <form #f="ngForm" (ngSubmit)="saveProduct(f.value)">
        <div class="form-group">
              <label for="name">Designation</label>
              <input ngModel placeholder="Designation" type="text" name="name" id="name" class="form-control">
            </div>
            
          <div class="form-group">
            <label for="unitPrice">Prix</label>
            <input ngModel placeholder="Price" type="number" name="unitPrice" id="unitPrice" class="form-control">
          </div>
          <div class="form-group">
            <label for="quantity">Quantite</label>
            <input ngModel placeholder="Quantite" type="number" name="quantity" id="quantity" class="form-control">
          </div>
         
          <div class="form-group">
            <label for="materiaux">Materiaux du  produit </label>
            <select class="form-control" ngModel  name="materiaux" id="materiaux">
              <option value="">----------</option>
              <option  value="Gold">Gold</option>
              <option  value="Diamond">Diamond</option>
              <option  value="Silver">Silver</option>
            </select>
          </div>
          <div class="form-group">
            <label for="category">Categorie du produit </label>
            <select *ngIf="ProductCategories"  class="form-control" ngModel  name="category" id="category">
              <option value="">----------</option>
              <option *ngFor="let c of ProductCategories._embedded.productCategories" value="{{c.id}}">{{c.categoryName}}</option>
            </select>
          </div>
          <button class="btn btn-sm btn-primary">Ajouter</button>
        </form>
      </div>
  </div>

产品Java语言

@Entity
@Table(name="product")
@Data
public class Product {

 @Id
 @GeneratedValue(strategy = GenerationType.IDENTITY)
 @Column(name = "id")
 private Long id;

 @ManyToOne
 @JoinColumn(name = "category_id", nullable = false)
 private ProductCategory category;



 @Column(name = "sku")
 private String sku;

 @Column(name = "materiaux")
 private String materiaux;

[and other Attributes.............]

ProductCategory产品类别

@Table(name="product_category")
// @Data -- known bug
@Getter
@Setter
public class ProductCategory {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    @Column(name = "category_name")
    private String categoryName;

    @JsonManagedReference
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "category")
    private Set<Product> products;

}

Answer 1

创建新产品时，您需要指定类别ID。