EF one-to-many to assure the link with the main table.

sblb 1,166

Hi,
I would like to do a link between main table Developer & a table ActionList.

The ActionList take place in edit mode of my app to the address : "/developer/edit/{developerId:int}"

I try to use EF one-to-many to do the link between two tables

I structured the model class has below :

public partial class Developer  
     {  
         public int Id { get; set; }  
          public ICollection<ActionsList>? ActionsLists { get; set; }  
  }  
      
  public class ActionsList  
     {  
         [Key]     
         public int ActionId { get; set; }              
           
         public DateTime ProductionDate { get; set; }  
              
         public int DeveloperId { get; set; }  
         public Developer Developer { get; set; }  
      
     }

application data :

 public class ApplicationDBContext : DbContext  
     {  
         public ApplicationDBContext(DbContextOptions<ApplicationDBContext> options) : base(options)  
         {  
         }  
         public DbSet<Developer> Developers { get; set; }  
         public DbSet<ActionsList> ActionsLists { get; set; }  
                     
          
         protected override void OnModelCreating(ModelBuilder modelBuilder)  
         {  
             modelBuilder.Entity<ActionsList>()  
                         .HasOne<Developer>(s => s.Developer)  
                         .WithMany(g => g.ActionsLists)  
                         .HasForeignKey(s => s.DeveloperId);         
         }     
          
       }

when I want to add the actions in page https://localhost:44354/developer/edit/1 this means all actions for developerId = 1 ; any value has posted in ActionList.

But when I've put the break point await http.PostAsJsonAsync("api/actionslist", act); I see that ActionId = null .

I guess that I set up EF one-to-many wrong!

Can you help me how to link the two tables? (This is the first time I've done this)

Thanks in advance

Zhi Lv - MSFT 32,021 Reputation points Microsoft Vendor

2022-11-14T02:14:18.127+00:00

Hi @sblb ,

The One-to-Many configuration seems correct in above post. More detail information about One-to-Many relationship, see :

One-to-Many Relationship Conventions in Entity Framework Core

Configure One-to-Many Relationships using Fluent API in Entity Framework Core.

But when I've put the break point await http.PostAsJsonAsync("api/actionslist", act); I see that ActionId = null .

Do you mean after calling the API method, the ActionId in the return data is null? From your code, the ActionId is the primary key, by default it is identity and will auto-insert, if it is null, first, you can check the database via the SSMS, whether the ActionsList table contains the relates data. Second, you can check the API method, whether it get the correct data from the database, and the return data is not null. If the issue relates the API method, can you share the relate code?

Accepted answer

AgaveJoe 26,146

Against my better judgement, I created an example. This is an example NOT a solution. In production code you would NOT pass entities between the client and Web API! Typically you would designed a data interrace and pass poco classes.

I used followed the following documentation which I have provided many times over many of your threads.

Tutorial: Create a web API with ASP.NET Core
Saving Related Data

Entities

    public partial class Developer  
    {  
        public int DeveloperId { get; set; }  
        public List<ActionItem>? ActionItems { get; set; }  
    }  
  
    public class ActionItem  
    {  
        public int ActionItemId { get; set; }  
        public string? Tilte { get; set; }  
        public string? Description { get; set; }  
        public string? State { get; set; }  
        public DateTime? OpenDate { get; set; }  
        public DateTime? PlanDate { get; set; }  
        public DateTime? CloseDate { get; set; }  
  
        public int DeveloperId { get; set; }  
        public Developer? Developer { get; set; }

Related data configuration

        protected override void OnModelCreating(ModelBuilder modelBuilder)  
        {  
            modelBuilder.Entity<ActionItem>()  
                .HasOne(d => d.Developer)  
                .WithMany(d => d.ActionItems);  
        }

Controller

    [Route("api/[controller]")]  
    [ApiController]  
    public class DeveloperActionController : ControllerBase  
    {  
        private readonly WebApiSqliteContext _context;  
        public DeveloperActionController(WebApiSqliteContext context)  
        {  
            _context = context;  
        }  
        // GET: api/<DeveloperActionController>  
        [HttpGet]  
        public IEnumerable<Developer> GetDevelopersWithActions()  
        {  
            return _context.Developers.Include(a => a.ActionItems).ToList();  
        }  
  
        // GET api/<DeveloperActionController>/5  
        [HttpGet("{id}")]  
        public async Task<ActionResult<Developer>> GetDeveloperActions(int id)  
        {  
            Developer? developer = await _context.Developers  
                .Include(a => a.ActionItems)  
                .FirstOrDefaultAsync(d => d.DeveloperId == id);  
  
            if (developer == null)  
            {  
                return NotFound();  
            }  
  
            return Ok(developer);  
        }  
  
        // POST api/<DeveloperActionController>  
        [HttpPost]  
        public async Task<ActionResult<Developer>> PostAsync([FromBody] Developer developer)  
        {  
            _context.Developers.Add(developer);  
            await _context.SaveChangesAsync();  
  
            return CreatedAtAction(nameof(GetDeveloperActions), new { id = developer.DeveloperId }, developer);  
        }  
  
        // PUT api/<DeveloperActionController>/5  
        [HttpPut("{id}")]  
        public async Task<ActionResult<Developer>> Put(int id, [FromBody] ActionItem actionItem)  
        {  
            Developer? developer = await _context.Developers  
                .Include(a => a.ActionItems)  
                .FirstOrDefaultAsync(d => d.DeveloperId == id);  
  
            if (developer == null)  
            {  
                return NotFound();  
            }  
  
            developer.ActionItems.Add(actionItem);  
            await _context.SaveChangesAsync();  
  
            return CreatedAtAction(nameof(GetDeveloperActions), new { id = developer.DeveloperId }, developer);  
  
        }  
  
        // DELETE api/<DeveloperActionController>/5  
        [HttpDelete("{id}")]  
        public async Task<IActionResult> Delete(int id)  
        {  
            Developer? developer = await _context.Developers  
                .Include(a => a.ActionItems)  
                .FirstOrDefaultAsync(d => d.DeveloperId == id);  
  
            if (developer == null)  
            {  
                return NotFound();  
            }  
  
            _context.Remove(developer);  
  
            await _context.SaveChangesAsync();  
  
            return NoContent();  
        }  
    }

Post data

{  
  "developerId": 0,  
  "actionItems": [  
    {  
      "actionItemId": 0,  
      "tilte": "Action Title",  
      "description": "Description",  
      "state": "State",  
      "openDate": "2022-11-17",  
      "planDate": "2022-11-17",  
      "closeDate": "2022-11-17",  
      "developerId": 0  
    }  
  ]  
}

Put data

{  
  "actionItemId": 0,  
  "tilte": "Action Title 2",  
  "description": "Description 2",  
  "state": "State 2",  
  "openDate": "2022-11-18",  
  "planDate": "2022-11-18",  
  "closeDate": "2022-11-18",  
  "developerId": 1  
}

Configuration is needed to return a entity otherwise you'll get an error.

builder.Services.AddControllers().AddJsonOptions(x =>  
                x.JsonSerializerOptions.ReferenceHandler = ReferenceHandler.IgnoreCycles);

13 additional answers

sblb 1,166

If you changed your mind and want to add a single ActionItem to a Developer then show this action.

I don't change ; I want several ACtionItem for one Developer row so the method one-to-many seems appropriate.

share where you are following the pattern shown in the Saving Related Data

here related-data

Class model Developer and ActionItem

 public partial class Developer  
    {  
        public int Id { get; set; }  
        public List<ActionItem>? ActionItems { get; set; }  
    }  

 public class ActionItem  
    {  
        [Key]  
        public int ActionId { get; set; }         
        public string? Tilte { get; set; }  
        public string? Description { get; set; }          
        public string? State { get; set; }          
        public DateTime? OpenDate { get; set; }         
        public DateTime? PlanDate { get; set; }         
        public DateTime? CloseDate { get; set; }  

        public int Id { get; set; }  
        public Developer? Developer { get; set; }  
    }

The column DeveloperId is created in table ActionItem, see below initial migration

 constraints: table =>  
                {  
                    table.PrimaryKey("PK_ActionItems", x => x.ActionId);  
                    table.ForeignKey(  
                        name: "FK_ActionItems_Developers_DeveloperId",  
                        column: x => x.DeveloperId,  
                        principalTable: "Developers",  
                        principalColumn: "Id");  
                });

sblb 1,166

Thanks to your proposition.
But it's doesn't work.

I don't obtain e.g Developer row (id=1) with several actions in page edit.

In your class model you use DeveloperId inn my side I use Id for two class.

In edit page in @Aidan Wick I call the post method as below :

 async Task CreateActionList()  
    {          
        await http.PostAsJsonAsync("api/developeractions", act);  
        uriHelper.NavigateTo($"/developer/edit/{developerId}");  
    }

Have you an idea why I didn't populate the ActionITem?

I have also the developercontroller

    [HttpGet]  
    public async Task<IActionResult> Get()  
    {  
        var devs = await _context.Developers.ToListAsync();  
        return Ok(devs);  
    }  

    [HttpGet("{id}")]  
    public async Task<IActionResult> Get(int id)  
    {  
        var dev = await _context.Developers.FirstOrDefaultAsync(a => a.Id == id);  
        return Ok(dev);  
    }         

    //Take a number ECO  
    [HttpGet("GenearteEcoById/{id}")]  
    public async Task<ActionResult<Developer>> GenearteEcoById(int id)  
    {  
        var developer = await _context.Developers.FindAsync(id);  
        if (developer == null)  
        {  
            return NotFound();  
        }  
        if (developer.ECOYear == 0 && developer.ECOCount == 0 && developer.ECOSelected==true)  
        {  
            var values = await GenerateEcoByIdAsync(id);  
            developer.ECOYear = values.Year;  
            developer.ECOCount = values.Count;  
            await _context.SaveChangesAsync();  
        }  
        else if(developer.ECOSelected == false)  
        {  
            developer.ECOYear = 0;  
            developer.ECOCount = 0;  
            await _context.SaveChangesAsync();  

        }  

        return developer;  
    }  
      
    private async Task<YearCount> GenerateEcoByIdAsync(int id)  
    {  
        if (!await _context.Developers.AnyAsync(d => d.ECOYear == DateTime.Now.Year))  
        {  
            return new YearCount() { Count = 1, Year = DateTime.Now.Year };  
        }  

        int max = await _context.Developers.Where(d => d.ECOYear == DateTime.Now.Year).MaxAsync(d => d.ECOCount) + 1;  
        return new YearCount() { Count = max, Year = DateTime.Now.Year };  
    }  

    //Creates a new Developer with the passed developer object data AND take ECR Number  
    [HttpPost]  
    public async Task<IActionResult> Post(Developer developer)  
    {  
                 
        YearCount dev = await IncrementDeveloperIdAsync();  

        developer.Year = dev.Year;  
        developer.Count = dev.Count;  

        _context.Add(developer);  
        await _context.SaveChangesAsync();  
        return Ok(developer.Id);  
    }        
     
    //Take the number ECR  
    private async Task<YearCount> IncrementDeveloperIdAsync()  
    {  
        if (!await _context.Developers.AnyAsync(d => d.Year == DateTime.Now.Year))  
        {  
            return new YearCount() { Count = 1, Year = DateTime.Now.Year };  
        }  

        int max = await _context.Developers.Where(d => d.Year == DateTime.Now.Year).MaxAsync(d => d.Count) + 1;  
        return new YearCount() { Count = max, Year = DateTime.Now.Year };  
    }  

    //Modifies an existing developer record.  
    [HttpPut]  
    public async Task<IActionResult> Put(Developer developer)  
    {  
        _context.Entry(developer).State = EntityState.Modified;  
        await _context.SaveChangesAsync();  
        return NoContent();  
    }  

    [HttpDelete("{id}")]  
    public async Task<IActionResult> Delete(int id)  
    {  
        var dev = new Developer { Id = id };  
        _context.Remove(dev);  
        await _context.SaveChangesAsync();  
        return NoContent();  
    }

AgaveJoe 26,146 Reputation points

2022-11-18T18:46:01.617+00:00

But it's doesn't work.

Works perfectly on my end. You must be doing something wrong.

I don't obtain e.g Developer row (id=1) with several actions in page edit.

you really need to learn how to troubleshoot your code. If you're updating an ActionItem and the ActionItemId is unique then you should be able to update that specific record by Id. If the record is not updating then, most likely, there is a problem with the code that populates the "act" type. Set a breakpoint and view the property values to make sure the code is setting the DeveloperId, ActionItemId, and any other fields that are required to properly update the record.

In your class model you use DeveloperId inn my side I use Id for two class.

Confused! I used your schema and your schema has a DeveloperId as a foreign key in ActionItem and DeveloperId is a primary key in Developer. If there is another class with a developed, that's fantastic but how does the other class have anything to do with the only two classes you've shared on the forum?

Have you an idea why I didn't populate the ActionITem?

There are bugs in your code and/or design. Have you tried using swagger to test the action? If the action is working as expected then the problem is with the code that sends the request.

You are not a new developer. Run your code through the Visual Studio debugger to find where the code stops working as expected.

Unfortunately, the controller you posted has nothing to do with ActionItem?!!!! What are you doing????
sblb 1,166 Reputation points

2022-11-18T19:02:43.553+00:00

Unfortunately, the controller you posted has nothing to do with ActionItem?!!!! What are you doing????

I ve two controllers Developer Controller and developeractionscontroller. The last controller is like you except key's name.
In developer class I use the Id
In actionsitem class I use the actionid
AgaveJoe 26,146 Reputation points

2022-11-18T21:05:06.627+00:00
In actionsitem class I use the actionid

I create a action to add an ActiobnItem and it just works.

// POST api/<DeveloperActionController>/AddAction [HttpPost("/api/DeveloperAction/AddActionItem")] public async Task<ActionResult<Developer>> PostActionItem([FromBody] ActionItem actionItem) { _context.ActionItems.Add(actionItem); await _context.SaveChangesAsync(); return CreatedAtAction(nameof(GetDeveloperActions), new { id = actionItem.DeveloperId }, actionItem); }

The payload is the same as I posted above.

{ "actionItemId": 0, "tilte": "Action Title 2", "description": "Description 2", "state": "State 2", "openDate": "2022-11-18", "planDate": "2022-11-18", "closeDate": "2022-11-18", "developerId": 1 }

For the fourth time! Most likely the error is in the Blazor Application making the call. You have a lot of experience and should be able to single step through the code to find the bugs. Use swagger, which comes default in Web API, to test the action. If the action is able to add the ActionItem then clearly the issue is elsewhere. Most likely the client making the HTTP call which is the Blazor application has problems.

I'm not sure what else I can do for you.
sblb 1,166 Reputation points

2022-11-19T17:45:32.85+00:00
Thanks to your proposition. I will try it.

As you do understand, I've two controllers DeveloperController and DeveloperActionController.
I don't think that there is a problem with Http because when I use only single action as below the ACtionItem is populated.

[HttpPost] public async Task<IActionResult> Post(ActionItem actions) { _contexts.Add(actions); await _contexts.SaveChangesAsync(); return Ok(actions.ActionId); }

I think I've to update the DeveloperControler to include ActionItems.
I come back after to have this update!!

sblb 1,166 Reputation points

2022-11-19T18:04:28.74+00:00

I've made any corection for moment
You right there is status 400 in dev tools.

Also I've this message in devtools. I don't understand because I am in edit mode and this field is not required only in create mode
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sblb 1,166 Reputation points

2022-11-20T09:15:41.247+00:00

I have removed the [required] annotations and I no longer have an error.
However, the ActionItem table is still not filled.

When I'm in the developer/edit mode I want to add an action; and surprise I add a line in developer. really I don't understand!

in address : https://localhost:44354/developer/edit/8 I added the button to add the actions.
When I validate the create button I create a row in developer while I want to create an action for the developer/edit/8
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AgaveJoe 26,146 Reputation points

2022-11-20T12:19:35.85+00:00

Seriously?! For over five days the browser's dev tools reported an error and you did not bother to look? It takes a few seconds to open dev tools. I get the feeling your effort is lacking a bit.

I've already explained how to troubleshoot the code. Use the Swagger tool to debug the Web API actions. Once you have the Web API actions working as expected then use the network view in the browser's dev tools to verify the Blazor application is sending a proper JSON payload.

This is basic programming. Troubleshoot and fix your code.

sblb 1,166 Reputation points

2022-11-20T18:18:51.92+00:00

result of the devtool
A s you can see I can write in Action but it is not post in ActionItem.
Plus the action is created in Developer table not in page edit/8

I think it's a route problem

se the Swagger tool to debug the Web API actions.

Swagger does not working. my app is blazor wasm core .net6.

AgaveJoe 26,146 Reputation points

2022-11-20T18:37:36.547+00:00

As you can see I can write in Action but is not post in ActionItem.

The last URL you shared goes to the developer controller not an ActionItem controller.

https://localhost:44354/developer/edit/8

If you want to call the ActionItem controller then change the URL.

Swagger does not working. my app is blazor wasm core .net6.

Nonsense. Swagger comes default with the Web API template and you're clearly calling Web API. If you need to add Swagger then it is two lines of code!

You have a lot of experience on these forums and I've provided this type of advice over several months. It seems you simply do not have the skills and you're not trying to move forward. I'm not sure how to help you.

sblb 1,166 Reputation points

2022-11-20T19:54:40.71+00:00

Nonsense. Swagger comes default with the Web API template and you're clearly calling Web API.

Sorry, but I had to install swagger via nugget's package.

in program.cs in server project i've put

builder.Services.AddSwaggerGen(); ... app.UseSwagger(); app.UseSwagger(); app.UseSwaggerUI(c => { c.SwaggerEndpoint("/swagger/v1/swagger.json", "AppWeb"); });

I received the message error : Swashbuckle.AspNetCore.SwaggerGen.SwaggerGeneratorException: Ambiguous HTTP method for action - AppWeb.Server.Controllers.ServerMethodsController.MonthlyStats (AppWeb.Server). Actions require an explicit HttpMethod binding for Swagger/OpenAPI 3.0

AgaveJoe 26,146 Reputation points

2022-11-20T20:34:38.77+00:00

Most likely there are mistakes in the Web API application. simply enter https://localhost:44354/swagger/v1/swagger.json in your browser's address bar to see the error.

You can also look up this very common error on the internet. You really need to learn how to troubleshoot your code.

sblb 1,166 Reputation points

2022-11-20T20:56:02.69+00:00

I will deal with this topic after solving the problem with developeractionscontroller

sblb 1,166 Reputation points

2022-11-20T20:59:46.113+00:00

The last URL you shared goes to the developer controller not an ActionItem controller.

in code behind in edit page

async Task CreateActionList() { await http.PostAsJsonAsync($"api/developeractions", act); uriHelper.NavigateTo($"/developer/edit/{developerId}"); }

When I've put a breakpoint here I'm going to developeractions and I see the data I've put in interface. but It is not populate ACtionItem??

AgaveJoe 26,146 Reputation points

2022-11-20T22:22:17.473+00:00

When I've put a breakpoint here I'm going to developeractions and I see the data I've put in interface

Unclear.... the "act" type property values are populated as expected? If so, share the property names and values. Use the visual Studio debugger and/or the browser's dev tools to view the names/values.

but It is not populate ACtionItem??

What's not populated? The action's parameters? Did you set a breakpoint in the action? Or are you guessing?

You really should get Swagger working so you can verify if the action is working as expected. The problem is you have no idea if the issue in in the Blazor application or action. Standard troubleshooting is about eliminating possible problems. Get swagger working so you can troubleshoot. Otherwise use a tool like PostMan.
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