Post request to database associated with primary and foreign key in web api using Entity Framework

Question

I have a database with three tables with primary and foreign key association .

I am using Web API and Entity Framework to auto generate methods. I have been successful doing that. But I want to insert into a table with foreign key separately.

Currently, I am able to get a JSON object for the main table which has primary key and navigation properties to the table with a foreign key.

I have created the web api using auto generate read write action methods like .

I am able to access the json object for floors database and accordingly for Meter and Router . So , I have a post method "/api/floorinfoes" with POST . But , what to do , if i want to insert separately into RouterInfo table and MeterInfo table .Eg: If i want to insert one row in MeterInfoes table, then how to proceed with that .

Answer 1

If you want to insert one row in MeterInfoes Table.

public class MeterInfo
{
        [Key]
        public int MeterId { get; set; }
        public string MeterName { get; set; }

        public int? FloorId { get; set; }

        [ForeignKey("FloorId")]
        public FloorInfo FloorInfo { get; set; }
}

Add your entities to DbContext, if not done already

public class DbContext : IdentityDbContext<IdentityUser>
{

        public DbSet<FloorInfo> FloorInfos { get; set; }
        public DbSet<MeterInfo> MeterInfos { get; set; }
        public DbSet<RouterInfo> RouterInfos { get; set; }
}

Create a new controller MeterInfoController or auto generate using scaffolding

public class MeterInfoController : ApiController
{

    public IHttpActionResult Post(MeterInfo meterInfo)
    {
        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }

         db.MeterInfo.Add(meterInfo);
         db.SaveChanges();

        return Ok(meterInfo);
    }
}

To consume this endpoint, for example:

Url : /api/MeterInfo

If you know the FloorId

   Post Data : {"MeterId": 1, "MeterName" : "Test" , "FloorId" : 10 } 

If you do not know the FloorId, but make sure FloorId in MeterInfo is nullable

 Post Data:  {"MeterId": 1, "MeterName" : "Test"} 

I think the answer is to auto generate API Controllers for both MeterInfo and RouterInfo.