如何使用 .net core 和 neo4j 进行 Post 操作

Question

I am very new at .Net Core and Neo4j. I want to make Wep Api for CRUD operations using Neo4jClient.I have a Book class and its controller. Also I have Author and its controller class. I want to make Post operation,but I cannot. Postman returns BadRequest(). So How can I solve this? What is the problem?

Here is my source code for Book.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace NEO4j.Models
{
    public class Book
    {

        public int Id { get; set; }
        public string Title { get; set; }
        public List<string> CategoryCodes { get; set; }
    }
}

BookController.cs

using Microsoft.AspNetCore.Mvc;
using NEO4j.Models;
using NEO4j.Services;
using Neo4jClient;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;

namespace NEO4j.Conrollers
{
    [Route("api/book")]
    public class BookController : Controller
    {
        private static int uniqueId=1;
        public string title { get; set; }
        public List<string> category { get; set; }

        private static BookService bookService;
        private static CategoryService categoryService;

        static BookController()
        {
            bookService = new BookService();
            categoryService = new CategoryService();
        }

        [HttpGet]
        public ActionResult Get()
        {
            var graphClient = new GraphClient(new Uri("http://localhost:7474/db/data"), "neo4j", "1234");
            graphClient.Connect();

            var data = graphClient.Cypher
               .Match("(m:Book)")
               .Return<Book>("m")
               .Results.ToList();

            return Ok(data.Select(c => new { book = c }));
        }


        [HttpPost]
        public ActionResult Post([FromBody] Book book) {

            var client = new GraphClient(new Uri("http://localhost:7474/db/data"), "neo4j", "1234");
            client.Connect();


            if (book == null)
                return BadRequest();

            if (!ModelState.IsValid)
                return BadRequest(ModelState);

            var newBook = new Book { Id = uniqueId, Title = title, CategoryCodes = category };
            client.Cypher
                .Merge("(book:Book { Id: {uniqueId} ,Title:{title},CategoryCodes:{category}})")
                .OnCreate()
                .Set("book = {newBook}")
                .WithParams(new
                {
                    uniqueId =newBook.Id,
                    title = newBook.Title,
                    category = newBook.CategoryCodes,
                    newBook
                })
                .ExecuteWithoutResults();

             uniqueId++;
             return Ok(newBook);
        }

    }
}

Answer 1

Only for the ASP.Net Core part:

localhost:63654/api/book {"Title":"Deep Learning", "CategoryCodes": "5"}

book is null

1. How you make your request (in your case, Postman ) matters - which is why I asked you to provide. So Headers and such are important.

   Sending JSON via Postman:

    POST /api/test HTTP/1.1 Host: localhost:63654 Content-Type: application/json Cache-Control: no-cache Postman-Token: 51081616-c62d-c677-b5ab-37d428018db5 {"Title":"Deep Learning", "CategoryCodes": ["1","2","3"]}

   Note the Content-Type Header

2. CategoryCodes in our Book model is a List , so you have to set a "list" (array) for its value as shown above "CategoryCodes": ["1","2","3"]

Hth..