C#•16mo ago

❔ Entity Framework, How To Join Second Table To Third Table In The First Table?

Hi i want to join table city to area like picture below, but i got an error like this

System.ArgumentException: The properties expression 'ab => Convert(ab.City.AreaId, Object)' is not valid. The expression should represent a simple property access: 't => t.MyProperty'. When specifying multiple properties use an anonymous type: 't => new { t.MyProperty1, t.MyProperty2 }'. (Parameter 'propertyAccessExpression')

System.ArgumentException: The properties expression 'ab => Convert(ab.City.AreaId, Object)' is not valid. The expression should represent a simple property access: 't => t.MyProperty'. When specifying multiple properties use an anonymous type: 't => new { t.MyProperty1, t.MyProperty2 }'. (Parameter 'propertyAccessExpression')

anyone know how to do it properly? im only know to join the first and second table and still learning ty.

7 Replies

Angius•16mo ago

Just so you know, builder.Property(x => x.Prop) without actually configuring that property is useless Also, how do your models look? The error, of course, is that a foreign key has to be a property Not a property of an object So ab.City.AreaId is not valid

FROP•16mo ago

welp i think i could cheat like that xD it was a simple model like this

public class AreaBranch
{
  public long Id {get; set;}
  public long CityId {get; set;}
  xxx property
  public virtual City {get; set;}
  public virtual Area {get; set;}
}
public class City
{
  public long Id {get; set;}
  public long AreaId {get; set;}
  xxx property
}
public class Area
{
  public long Id {get; set;}
  xxx property
}

public class AreaBranch
{
  public long Id {get; set;}
  public long CityId {get; set;}
  xxx property
  public virtual City {get; set;}
  public virtual Area {get; set;}
}
public class City
{
  public long Id {get; set;}
  public long AreaId {get; set;}
  xxx property
}
public class Area
{
  public long Id {get; set;}
  xxx property
}

Angius•16mo ago

Ah, a many-to-many relationship with additional data on the pivot table, basically? Uh, kinda Because City and Area also have a direct relationship

FROP•16mo ago

yeah prob like that, Area it should be Provience but i forgot to change the name my man, i accidentally found it! just change my linq query from this

.Select(areaBranch => new AreaBranch
                    {
                        Id = areaBranch.Id,
                        BranchId = areaBranch.BranchId,
                        CityId = areaBranch.CityId,
                        Name = areaBranch.Name,
                        Status = areaBranch.Status,
                        City = areaBranch.City,
                    })

.Select(areaBranch => new AreaBranch
                    {
                        Id = areaBranch.Id,
                        BranchId = areaBranch.BranchId,
                        CityId = areaBranch.CityId,
                        Name = areaBranch.Name,
                        Status = areaBranch.Status,
                        City = areaBranch.City,
                    })

to this

_persistence.AsQueryable()
                    .Select(areaBranch => new AreaBranch
                    {
                        Id = areaBranch.Id,
                        BranchId = areaBranch.BranchId,
                        CityId = areaBranch.CityId,
                        Name = areaBranch.Name,
                        Status = areaBranch.Status,
                        City = areaBranch.City,
                        Area = areaBranch.City.Area
                    })
                    .ToList());

_persistence.AsQueryable()
                    .Select(areaBranch => new AreaBranch
                    {
                        Id = areaBranch.Id,
                        BranchId = areaBranch.BranchId,
                        CityId = areaBranch.CityId,
                        Name = areaBranch.Name,
                        Status = areaBranch.Status,
                        City = areaBranch.City,
                        Area = areaBranch.City.Area
                    })
                    .ToList());

also add prop public virtual Area { get; set; } in City Model and remove Join Area in AreaBranch Builder here some result from my JSON

{
        "branchId": "DF",
        "cityId": 1,
        "name": "Default",
        "status": false,
        "city": {
            "cityCode": "default_in",
            "cityName": "default_in",
            "areaId": 11,
            "area": {
                "name": "default_in",
                "cityName": "default_in",
                "status": false,
                "countryId": "IN",
                "parentId": null,
                "id": 11
            },
            "id": 1
        },
        "area": {
            "name": "default_in",
            "cityName": "default_in",
            "status": false,
            "countryId": "IN",
            "parentId": null,
            "id": 11
        },
        "id": 1
    }

{
        "branchId": "DF",
        "cityId": 1,
        "name": "Default",
        "status": false,
        "city": {
            "cityCode": "default_in",
            "cityName": "default_in",
            "areaId": 11,
            "area": {
                "name": "default_in",
                "cityName": "default_in",
                "status": false,
                "countryId": "IN",
                "parentId": null,
                "id": 11
            },
            "id": 1
        },
        "area": {
            "name": "default_in",
            "cityName": "default_in",
            "status": false,
            "countryId": "IN",
            "parentId": null,
            "id": 11
        },
        "id": 1
    }

idk why if i exclude Area = areaBranch.City.Area from my linq, my City didnt want to show up Area, but hei if its work its work. anyway ty that was fast

Unknown User•16mo ago

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MODiX•16mo ago

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Accord•16mo ago

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❔ Entity Framework, How To Join Second Table To Third Table In The First Table?