I have 3 table is article, comment and image:

create table article (
   id int not null auto_increment,
   views int default null,
   title varchar(255) not null,
   status tinyint default 1,
   content text default null,
   created_date datetime default null,
   updated_date datetime default null,
   created_by int default null,
   updated_by int default null,
   primary key (id)
);

create table comment (
   id int not null auto_increment,
   content text default null,
   favorite int default null,
   created_date datetime default null,
   updated_date datetime default null,
   created_by int default null,
   updated_by int default null,
   article_id int default null,
   primary key (id)
);

create table image (
   id int not null auto_increment,
   id_obj int default null,
   url varchar(255) not null,
   thumbnail tinyint default null,
   type varchar(50) default null,
   primary key (id)
);

Here is my DB Diagram:

Image table don't have foreign key with article table and comment table. Image table have two columns: id_obj and type. When I save id_obj = 2 and type = comment, it's mean record id 2 of comment table. On the contrary, id_obj = 3 and type = article, it's mean record id 3 of article table. How to create POST method for article that can add and save images to the image table? I tried to create but can only save data to DB and no image.

This is the Interface:

public interface IArticleService
{
    public Task<int> Create(ArticleRequest request);
}

This is Service:

public class ArticleService : IArticleService
{
        private readonly DbContext _context;

        public ArticleService(DbContext context)
        {
            _context = context;
        }

        public async Task<int> Create(ArticleRequest request)
        {
            var article = new Articles()
            {
                Views = request.Views,
                Title = request.Title, 
                Status = request.Status,
                Content = request.Content,
                CreatedDate = request.CreatedDate,
                UpdatedDate = request.UpdatedDate,
                CreatedBy = request.CreatedBy,
                UpdatedBy = request.UpdatedBy
            };

            _context.Articles.Add(article);

            return await _context.SaveChangesAsync();
        }
}

This is Post method:

[HttpPost]
public async Task<IActionResult> Create([FromBody] ArticleRequest request)
{
    var status = await _articleService.Create(request);            
    return Ok(status);
}

Looking forward to receiving an answer, or a similar post.

CodePudding user response：

There might be some details missing, but from the info you've provided, since your tables aren't "connected", so it is not enough to just say

public async Task<int> Create(ArticleRequest request)
    {
        var article = new Articles()
        {
            Views = request.Views,
            Title = request.Title, 
            Status = request.Status,
            Content = request.Content,
            CreatedDate = request.CreatedDate,
            UpdatedDate = request.UpdatedDate,
            CreatedBy = request.CreatedBy,
            UpdatedBy = request.UpdatedBy
        };

        _context.Articles.Add(article);

        return await _context.SaveChangesAsync();
    }

you would need something along the lines of

public async Task<int> Create(ArticleRequest request)
    {
        var article = new Articles()
        {
            Views = request.Views,
            Title = request.Title, 
            Status = request.Status,
            Content = request.Content,
            CreatedDate = request.CreatedDate,
            UpdatedDate = request.UpdatedDate,
            CreatedBy = request.CreatedBy,
            UpdatedBy = request.UpdatedBy
        };

        _context.Articles.Add(article);
        var image = new Image()
        {
            SomeImageProperty = request.someImageProperty,
            .
            .
            .
        };
        _context.Images.Add(image);

        return await _context.SaveChangesAsync();
    }