Entity Framework Core: „SqlNullValueException: Daten sind Null.“ Wie kann ich Fehler beheben? ⇐ C#

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 Entity Framework Core: „SqlNullValueException: Daten sind Null.“ Wie kann ich Fehler beheben?

Post by Anonymous »

Ich verwende Entity Framework Core in einer ASP.NET Core-Anwendung und Controller-Aktion und habe weder am Arbeitscode noch an der Datenbank etwas geändert, kann aber nicht sagen, welche Abfrage von Entity Framework Core durchgeführt wird.

Die Controller-Aktion:

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[HttpGet]
// GET: Administration/Companies
public async Task Index()
{
var users = await UserManager.Users.ToListAsync();

var companyEditVMs = await DB.Companies
.OrderBy(company => company.CompanyId == 1
? "_" + company.CompanyName
: company.CompanyName
)
Select(a => new CompanyEditVM(HttpContext, a, users.Where(b => b.CompanyId == a.CompanyId)))
.ToListAsync();

return View(companyEditVMs);
}
Der Trace

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SqlNullValueException: Data is Null. This method or property cannot be called on Null values.
System.Data.SqlClient.SqlBuffer.get_String()
System.Data.SqlClient.SqlDataReader.GetString(int i)
lambda_method(Closure , DbDataReader )
Microsoft.EntityFrameworkCore.Storage.Internal.TypedRelationalValueBufferFactory.Create(DbDataReader dataReader)
Microsoft.EntityFrameworkCore.Query.Internal.AsyncQueryingEnumerable+AsyncEnumerator.BufferlessMoveNext(DbContext _, bool buffer, CancellationToken cancellationToken)
Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync(TState state, Func operation, Func verifySucceeded, CancellationToken cancellationToken)
Microsoft.EntityFrameworkCore.Query.Internal.AsyncQueryingEnumerable+AsyncEnumerator.MoveNext(CancellationToken cancellationToken)
Microsoft.EntityFrameworkCore.Query.Internal.AsyncLinqOperatorProvider+ExceptionInterceptor+EnumeratorExceptionInterceptor.MoveNext(CancellationToken cancellationToken)
System.Linq.AsyncEnumerable.Aggregate_(IAsyncEnumerable source, TAccumulate seed, Func accumulator, Func resultSelector, CancellationToken cancellationToken) in Aggregate.cs
KYC.Core.Areas.Commercial.Controllers.CompaniesController.Index() in CompaniesController.cs
-
[HttpGet]
// GET: Administration/Companies
public async Task Index()
{
var users = await UserManager.Users.ToListAsync();

var companyEditVMs = await DB.Companies
.OrderBy(company => company.CompanyId == 1
? "_" + company.CompanyName
: company.CompanyName
)
.Select(a => new CompanyEditVM(HttpContext, a, users.Where(b => b.CompanyId == a.CompanyId)))
.ToListAsync();
lambda_method(Closure , object )
Microsoft.Extensions.Internal.ObjectMethodExecutorAwaitable+Awaiter.GetResult()
Microsoft.AspNetCore.Mvc.Internal.ActionMethodExecutor+TaskOfActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, object controller, object[] arguments)
System.Threading.Tasks.ValueTask.get_Result()
Ich habe sogar versucht, nur var Companies = waiting DB.Companies.ToListAsync() auszuführen. und ich habe genau die gleiche Ausnahme.

Vielleicht möchte ich die von EF Core durchgeführte Abfrage abrufen können, um das manuell zu erledigen, damit ich versuchen kann, es herauszufinden Was stimmt mit der Abfrage nicht?

Ich frage mich, was möglicherweise passiert sein könnte. Vor allem, da andere Entitäten wie Benutzer oder Länder weiterhin aus der Datenbank abgerufen werden können.

Irgendeine Idee, wie ich das eigentliche zugrunde liegende Problem beheben kann?

[BEARBEITEN]

Das Einzige, was sich tatsächlich im „Code“ geändert hat, sind die Nuget-Referenzen. Ich habe im Grunde genommen so ziemlich alles aktualisiert, obwohl es nicht so war. Wenn ich keine Referenz im Code unterbreche, scheint es irgendwie zu ändern, wie EF Core ist (wilde Vermutung) Interpretieren der Datenbank.

Ich habe mein Git-Repository auf den Punkt zurückgesetzt, kurz bevor die Aktualisierung der Nuget-Pakete stattfand und alles funktionierte.,. Ich habe dann beschlossen, EntityFrameworkCore einfach von 2.0.2 auf 2.2.4 zu aktualisieren (habe es auch mit 2.2.0 versucht und am Ende das gleiche Ergebnis erhalten), und das Problem tritt erneut auf ... Ich bin mir nicht sicher, was sich zwischen 2.0.2 und 2.2 geändert hat. 0, um diese Ausnahme auszulösen (aber das Modell ist dasselbe, nur die EF Core-Version hat sich geändert)...

Hier ist die Entitätsdefinition, sie scheint automatisch erstellt worden zu sein. mit einem Werkzeug erzeugt aus der Datenbanktabelle/Schema:

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[Table("T_Companies")]
public partial class Company : INotifyPropertyChanging, INotifyPropertyChanged
{
public override string ToString()
{
return CompanyId + " " + CompanyName;
}

private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(string.Empty);

private int _CompanyId;

private string _CompanyName;

private int _CompanyTypeId;

private int _CountryId;

private string _CompanyVatNumber;

private string _CompanyStreetAddress;

private string _CompanyZipCode;

private string _CompanyCity;

private string _ContactLastName;

private string _ContactFirstName;

private bool? _Active;

private int? _AccountId;

private string _CallbackSalt;

private int? _UserSpaceId;

private string _Login;

private string _Pwd;

private bool _IsTechnicalAccount;

private DateTime? _StatusDate;

private int _BankStatusCode;

private string _PivotalAccount;

private CompanyType _CompanyType;

private Country _Country;

private bool _IsKycIdSent;

#region Extensibility Method Definitions
partial void OnLoaded();
partial void OnCreated();
partial void OnCompanyIdChanging(int value);
partial void OnCompanyIdChanged();
partial void OnCompanyNameChanging(string value);
partial void OnCompanyNameChanged();

partial void OnCompanyCityChanging(string value);
partial void OnCompanyCityChanged();
partial void OnCompanyZipCodeChanging(string value);
partial void OnCompanyZipCodeChanged();
partial void OnContactLastNameChanging(string value);
partial void OnContactLastNameChanged();
partial void OnActiveChanging(bool? value);
partial void OnActiveChanged();
partial void OnCompanyTypeIdChanging(int value);
partial void OnCompanyTypeIdChanged();
partial void OnCountryIdChanging(int value);
partial void OnCountryIdChanged();
partial void OnContactFirstNameChanging(string value);
partial void OnContactFirstNameChanged();
partial void OnCompanyVatNumberChanging(string value);
partial void OnCompanyVatNumberChanged();
partial void OnCompanyStreetAddressChanged();
partial void OnCompanyStreetAddressChanging(string value);
partial void OnAccountIdChanging(int? value);
partial void OnAccountIdChanged();
partial void OnCallbackSaltChanging(string value);
partial void OnCallbackSaltChanged();
partial void OnUserSpaceIdChanging(int? value);
partial void OnUserSpaceIdChanged();
partial void OnLoginChanging(string value);
partial void OnLoginChanged();
partial void OnPwdChanging(string value);
partial void OnPwdChanged();
partial void OnIsTechnicalAccountChanging(bool value);
partial void OnIsTechnicalAccountChanged();
partial void OnStatusDateChanging(DateTime? value);
partial void OnStatusDateChanged();
partial void OnBankStatusCodeChanging(int value);
partial void OnBankStatusCodeChanged();
partial void OnPivotalAccountChanging(string value);
partial void OnPivotalAccountChanged();
partial void OnIsKycIdSentChanging(bool value);
partial void OnIsKycIdSentChanged();

#endregion

public Company()
{
OnCreated();
}

[Key, Column("CompanyId"), DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int CompanyId
{
get =>  _CompanyId;
set
{
if (_CompanyId != value)
{
OnCompanyIdChanging(value);
SendPropertyChanging();
_CompanyId = value;
SendPropertyChanged("CompanyId");
OnCompanyIdChanged();
}
}
}

[DataType(DataType.Text), StringLength(1024), Column("CompanyName"), Required]
public string CompanyName
{
get => _CompanyName;
set
{
if (_CompanyName != value)
{
OnCompanyNameChanging(value);
SendPropertyChanging();
_CompanyName = value;
SendPropertyChanged("CompanyName");
OnCompanyNameChanged();
}
}
}

[Column("CompanyTypeId"), Required]
public int CompanyTypeId
{
get => _CompanyTypeId;
set
{
if (_CompanyTypeId != value)
{
OnCompanyTypeIdChanging(value);
SendPropertyChanging();
_CompanyTypeId = value;
SendPropertyChanged("CompanyTypeId");
OnCompanyTypeIdChanged();
}
}
}

[Column("CountryId"), Required]
public int CountryId
{
get => _CountryId;
set
{
if (CountryId != value)
{
OnCountryIdChanging(value);
SendPropertyChanging();
_CountryId = value;
SendPropertyChanged("CountryId");
OnCountryIdChanged();
}
}
}

[DataType(DataType.Text), StringLength(100), Column("CompanyCity"), Required]
public string CompanyCity
{
get => _CompanyCity;
set
{
if (_CompanyCity != value)
{
OnCompanyCityChanging(value);
SendPropertyChanging();
_CompanyCity = value;
SendPropertyChanged("CompanyCity");
OnCompanyCityChanged();
}
}
}

[DataType(DataType.Text), StringLength(100), Column("CompanyStreetAddress"), Required]
public string CompanyStreetAddress
{
get => _CompanyStreetAddress;
set
{
if (_CompanyStreetAddress != value)
{
OnCompanyStreetAddressChanging(value);
SendPropertyChanging();
_CompanyStreetAddress = value;
SendPropertyChanged("CompanyStreetAddress");
OnCompanyStreetAddressChanged();
}
}
}

[DataType(DataType.Text), StringLength(30), Column("CompanyVatNumber"), Required]
public string CompanyVatNumber
{
get => _CompanyVatNumber;
set
{
if (_CompanyVatNumber != value)
{
OnCompanyVatNumberChanging(value);
SendPropertyChanging();
_CompanyVatNumber = value;
SendPropertyChanged("CompanyVatNumber");
OnCompanyVatNumberChanged();
}
}
}

[DataType(DataType.Text), StringLength(10), Column("CompanyZipCode"), Required]
public string CompanyZipCode
{
get =>  _CompanyZipCode;
set
{
if (_CompanyZipCode != value)
{
OnCompanyZipCodeChanging(value);
SendPropertyChanging();
_CompanyZipCode = value;
SendPropertyChanged("CompanyZipCode");
OnCompanyZipCodeChanged();
}
}
}

[DataType(DataType.Text), StringLength(1024), Column("ContactLastName"), Required]
public string ContactLastName
{
get => _ContactLastName;
set
{
if (_ContactLastName != value)
{
OnContactLastNameChanging(value);
SendPropertyChanging();
_ContactLastName = value;
SendPropertyChanged("ContactLastName");
OnContactLastNameChanged();
}
}
}

[DataType(DataType.Text), StringLength(1024), Column("ContactFirstName"), Required]
public string ContactFirstName
{
get => _ContactFirstName;
set
{
if (_ContactFirstName != value)
{
OnContactFirstNameChanging(value);
SendPropertyChanging();
_ContactFirstName = value;
SendPropertyChanged("ContactFirstName");
OnContactFirstNameChanged();
}
}
}

[Column("Active"), Required]
public bool? Active
{
get => _Active;
set
{
if (_Active != value)
{
OnActiveChanging(value);
SendPropertyChanging();
_Active = value;
SendPropertyChanged("Active");
OnActiveChanged();
}
}
}

[Column("AccountId")]
public int? AccountId
{
get => _AccountId;
set
{
if (_AccountId != value)
{
OnAccountIdChanging(value);
SendPropertyChanging();
_AccountId = value;
SendPropertyChanged("AccountId");
OnAccountIdChanged();
}
}
}

[DataType(DataType.Text), StringLength(1024), Column("CallbackSalt")]
public string CallbackSalt
{
get => _CallbackSalt;
set
{
if (_CallbackSalt != value)
{
OnCallbackSaltChanging(value);
SendPropertyChanging();
_CallbackSalt = value;
SendPropertyChanged("CallbackSalt");
OnCallbackSaltChanged();
}
}
}

[Column("UserSpaceId")]
public int? UserSpaceId
{
get => _UserSpaceId;
set
{
if (_UserSpaceId != value)
{
OnUserSpaceIdChanging(value);
SendPropertyChanging();
_UserSpaceId = value;
SendPropertyChanged("UserSpaceId");
OnUserSpaceIdChanged();
}
}
}

[DataType(DataType.Text), StringLength(1024), Column("Login")]
public string Login
{
get => _Login;
set
{
if (_Login != value)
{
OnLoginChanging(value);
SendPropertyChanging();
_Login = value;
SendPropertyChanged("Login");
OnLoginChanged();
}
}
}

[DataType(DataType.Text), StringLength(1024), Column("Pwd")]
public string Pwd
{
get =>  _Pwd;
set
{
if (_Pwd != value)
{
OnPwdChanging(value);
SendPropertyChanging();
_Pwd = value;
SendPropertyChanged("Pwd");
OnPwdChanged();
}
}
}

[Column("IsTechnicalAccount"), Required]
public bool IsTechnicalAccount
{
get => _IsTechnicalAccount;
set
{
if (_IsTechnicalAccount != value)
{
OnIsTechnicalAccountChanging(value);
SendPropertyChanging();
_IsTechnicalAccount = value;
SendPropertyChanged("IsTechnicalAccount");
OnIsTechnicalAccountChanged();
}
}
}

[DataType(DataType.DateTime), Column("StatusDate")]
public DateTime? StatusDate
{
get => _StatusDate;
set
{
if (_StatusDate != value)
{
OnStatusDateChanging(value);
SendPropertyChanging();
_StatusDate = value;
SendPropertyChanged("StatusDate");
OnStatusDateChanged();
}
}
}

[Column("BankStatusCode")]
public int BankStatusCode
{
get => _BankStatusCode;
set
{
if (_BankStatusCode != value)
{
OnBankStatusCodeChanging(value);
SendPropertyChanging();
_BankStatusCode = value;
SendPropertyChanged("BankStatusCode");
OnBankStatusCodeChanged();
}
}
}

[DataType(DataType.Text), StringLength(255), Column("PivotalAccount")]
public string PivotalAccount
{
get => _PivotalAccount;
set
{
if (_PivotalAccount != value)
{
OnPivotalAccountChanging(value);
SendPropertyChanging();
_PivotalAccount = value;
SendPropertyChanged("PivotalAccount");
OnPivotalAccountChanged();
}
}
}

public List Resultats { get; set; }

public CompanyType CompanyType
{
get => _CompanyType;
set
{
var previousValue = _CompanyType;
if (previousValue != value)
{
SendPropertyChanging();
_CompanyType = value;
if (value != null)
{
CompanyTypeId = value.CompanyTypeId;
}
else
{
_CompanyTypeId = default;
}
SendPropertyChanged("CompanyType");
}
}
}

public Country Country
{
get => _Country;
set
{
var previousValue = _Country;
if (previousValue != value)
{
SendPropertyChanging();
_Country = value;
_CountryId = value?.CountryId ?? default;
SendPropertyChanged("Country");
}
}
}

[Column("IsKycIdSent"), Required]
public bool IsKycIdSent
{
get =>  _IsKycIdSent;
set
{
if (_IsKycIdSent != value)
{
OnIsKycIdSentChanging(value);
SendPropertyChanging();
_IsKycIdSent = value;
SendPropertyChanged("IsKycIdSent");
OnIsKycIdSentChanged();
}
}
}

public event PropertyChangingEventHandler PropertyChanging;

public event PropertyChangedEventHandler PropertyChanged;

protected virtual void SendPropertyChanging()
{
PropertyChanging?.Invoke(this, emptyChangingEventArgs);
}

protected virtual void SendPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}

private void Attach_Resultats(Resultat entity)
{
SendPropertyChanging();
entity.Company = this;
}

private void Detach_Resultats(Resultat entity)
{
SendPropertyChanging();
entity.Company = null;
}
}
und das zugehörige Tabellenerstellungsskript:

Code: Select all

create table T_Companies
(
CompanyId            int identity (10) identity
primary key nonclustered,
CompanyName          varchar(1024) not null,
CompanyTypeId        int           not null
constraint FK_Company_CompanyType
references T_CompanyTypes,
CountryId            int           not null
constraint FK_Company_Country
references T_Countries,
Active               bit           not null,
AccountId            int,
CallbackSalt         varchar(1024),
UserSpaceId          int,
Login                varchar(1024),
Pwd                  varchar(1024),
StatusDate           datetime(23, 3),
BankStatusCode       int           not null,
PivotalAccount       varchar(255),
IsTechnicalAccount   bit           not null,
CompanyStreetAddress varchar(256),
CompanyCity          varchar(256),
CompanyZipCode       varchar(10),
CompanyVatNumber     varchar(30),
ContactFirstName     varchar(20),
ContactLastName      varchar(20),
IsKycIdSent          bit           not null
)
go
[EDIT 2]

Für dasselbe Modell gilt dies (in der Projektdatei die Nuget-Referenzen) funktioniert

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während diese, nein:

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