We Keep Coding

How do I deal with this error where I can't update the database (EF)?

I've already made a similar application and these relationships worked - but I decided to make one change. Namely, the user can be both a dog walker and an owner. At this point the database does not want to update even though the migration is being created - (I'm using code first EF). This error pops up
Introducing FOREIGN KEY constraint 'FK_dbo.OwnerAdverts_dbo.Dogs_DogId' on table 'OwnerAdverts' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Could not create constraint or index. See previous errors.
This is how my classes look like - there are more of them, of course, but I present those that should have relations. The Dog should have a relationship with the User, as the** User** is its Owner (there can be no dog without an owner, but an owner without a dog). Then an advertisement(OwnerAdvert) is created, where the Dog is transferred to him. In addition, there is also an announcement of the walker(WalkerAdvert) to which the User is passed. -As I wrote, a user can be both a walker and an owner.
public class User:DOGModel
{
private int userId;
private string userName;
private string userSurname;
private EnumGender userGender;
private string userEmail;
private string userPassword;
private DateTime userDateOfBirth;
private string userPhone;
[Key]
public int UserId { get => userId; set => userId = value; }
public string UserName { get => userName; set => userName = value; }
public string UserSurname { get => userSurname; set => userSurname = value; }
public EnumGender UserGender { get => userGender; set => userGender = value; }
public string UserEmail { get => userEmail; set => userEmail = value; }
public string UserPassword { get => userPassword; set => userPassword = value; }
public DateTime UserDateOfBirth { get => userDateOfBirth; set => userDateOfBirth = value; }
public string UserPhone { get => userPhone; set => userPhone = value; }
public virtual List<WalkerAdvert> advert { get; set; }
public User()
{
UserId = 0;
UserId++;
}
public User(string userName, string userSurname, EnumGender userGender, string userEmail, string userPassword, string userDateOfBirth, string userPhone):this()
{
UserName = userName;
UserSurname = userSurname;
UserGender = userGender;
UserEmail = userEmail;
UserPassword = userPassword;
DateTime.TryParseExact(userDateOfBirth, new[] { "yyyy-MM-dd", "yyyy/MM/dd", "MM/dd/yy", "dd-MMM-yy" }, null, DateTimeStyles.None, out DateTime date);
UserDateOfBirth = date;
UserPhone = userPhone;
public class Dog
{
private int dogId;
private string dogName;
private string dogDescription;
private EnumSize dogSize;
private EnumActivityDemand dogActivityDemand;
private EnumDogGender dogGender;
private string dogBreed;
private DateTime dogDateOfBirth;
[Key]
public int DogId { get => dogId; set => dogId = value; }
public string DogName { get => dogName; set => dogName = value; }
public string DogDescription { get => dogDescription; set => dogDescription = value; }
public EnumSize DogSize { get => dogSize; set => dogSize = value; }
public EnumActivityDemand DogActivityDemand { get => dogActivityDemand; set => dogActivityDemand = value; }
public EnumDogGender DogGender { get => dogGender; set => dogGender = value; }
public string DogBreed { get => dogBreed; set => dogBreed = value; }
public DateTime DogDateOfBirth { get => dogDateOfBirth; set => dogDateOfBirth = value; }
[Required]
public virtual User DogOwner { get; set; }
[Required]
public int UserId { get; set; }
public virtual List<OwnerAdvert> advert { get; set; }
public Dog()
{
DogId= 0;
DogId++;
}
public Dog(string dogName, string dogDescription, EnumSize dogSize, EnumActivityDemand dogActivityDemand, EnumDogGender dogGender, string dogBreed, string dogDateOfBirth, User dogOwner):this()
{
DogName = dogName;
DogDescription = dogDescription;
DogSize = dogSize;
DogActivityDemand = dogActivityDemand;
DogGender = dogGender;
DogBreed = dogBreed;
DateTime.TryParseExact(dogDateOfBirth, new[] { "yyyy-MM-dd", "yyyy/MM/dd", "MM/dd/yy", "dd-MMM-yy" }, null, DateTimeStyles.None, out DateTime date);
DogDateOfBirth = date;
DogOwner = dogOwner;
}
public class OwnerAdvert:DOGModel
{
private int ownerAdvertId;
private string ownerAdvertCity;
private string ownerAdvertTitle;
private string ownerAdvertDescription;
private string ownerAdvertAmount;
private DateTime ownerAdvertDateAdded;
private DateTime ownerAdvertDateOfSerice;
private int ownerAdvertWalkingTime;
[Key]
public int OwnerAdvertId { get => ownerAdvertId; set => ownerAdvertId = value; }
public string OwnerAdvertCity { get => ownerAdvertCity; set => ownerAdvertCity = value; }
public string OwnerAdvertTitle { get => ownerAdvertTitle; set => ownerAdvertTitle = value; }
public string OwnerAdvertDescription { get => ownerAdvertDescription; set => ownerAdvertDescription = value; }
public string OwnerAdvertAmount { get => ownerAdvertAmount; set => ownerAdvertAmount = value; }
public DateTime OwnerAdvertDateAdded { get => ownerAdvertDateAdded; set => ownerAdvertDateAdded = value; }
public DateTime OwnerAdvertDateOfSerice { get => ownerAdvertDateOfSerice; set => ownerAdvertDateOfSerice = value; }
public int OwnerAdvertWalkingTime { get => ownerAdvertWalkingTime; set => ownerAdvertWalkingTime = value; }
public virtual Dog Dog { get; set; }
public int DogId { get; set; }
public OwnerAdvert()
{
OwnerAdvertId = 0;
OwnerAdvertId++;
}
public OwnerAdvert( Dog ownerAdvertDog, string ownerAdvertCity, string ownerAdvertTitle, string ownerAdvertDescription, string ownerAdvertAmount, DateTime ownerAdvertDateAdded, DateTime ownerAdvertDateOfSerice, int ownerAdvertWalkingTime):this()
{
Dog = ownerAdvertDog;
OwnerAdvertCity = ownerAdvertCity;
OwnerAdvertTitle = ownerAdvertTitle;
OwnerAdvertDescription = ownerAdvertDescription;
OwnerAdvertAmount = ownerAdvertAmount;
OwnerAdvertDateAdded = ownerAdvertDateAdded;
OwnerAdvertDateOfSerice = ownerAdvertDateOfSerice;
OwnerAdvertWalkingTime = ownerAdvertWalkingTime;
}
public class WalkerAdvert
{
private int walkerAdvertId;
private string walkerAdvertTitle;
private string walkerAdvertCity;
private decimal walkerAdvertAmount;
private string walkerAdvertDescription;
private DateTime walkerAdvertDateAdded;
public string WalkerAdvertTitle { get => walkerAdvertTitle; set => walkerAdvertTitle = value; }
public string WalkerAdvertCity { get => walkerAdvertCity; set => walkerAdvertCity = value; }
public decimal WalkerAdvertAmount { get => walkerAdvertAmount; set => walkerAdvertAmount = value; }
public string WalkerAdvertDescription { get => walkerAdvertDescription; set => walkerAdvertDescription = value; }
public DateTime WalkerAdvertDateAdded { get => walkerAdvertDateAdded; set => walkerAdvertDateAdded = value; }
[Key]
public int WalkerAdvertId { get => walkerAdvertId; set => walkerAdvertId = value; }
public virtual User Walker { get; set; }
public int UserId { get; set; }
public WalkerAdvert()
{
WalkerAdvertId = 0;
WalkerAdvertId++;
}
public WalkerAdvert(string walkerAdvertTitle, string walkerAdvertCity, decimal walkerAdvertAmount, string walkerAdvertDescription, DateTime walkerAdvertDateAdded, User walkerAdvertWalker) : this()
{
WalkerAdvertTitle = walkerAdvertTitle;
WalkerAdvertCity = walkerAdvertCity;
WalkerAdvertAmount = walkerAdvertAmount;
WalkerAdvertDescription = walkerAdvertDescription;
WalkerAdvertDateAdded = walkerAdvertDateAdded;
Walker = walkerAdvertWalker;
}
Similar questions have already happened, but I can't quite reproduce them on my example, I also attach what the DOGModel looks like
public class DOGModel : DbContext
{
// Your context has been configured to use a 'DOGModel' connection string from your application's
// configuration file (App.config or Web.config). By default, this connection string targets the
// 'DOGAppModern.DOGModel' database on your LocalDb instance.
//
// If you wish to target a different database and/or database provider, modify the 'DOGModel'
// connection string in the application configuration file.
public DOGModel()
: base("name=DOGModel")
{
}
public virtual DbSet<User> Users { get; set; }
public virtual DbSet<Dog> Dogs { get; set; }
public virtual DbSet<OwnerAdvert> OwnerAdverts { get; set; }
public virtual DbSet<WalkerAdvert> WalkerAdverts { get; set; }
}

Return the max Date

[Column, Nullable] public DateTime? ModifiedDate { get; set; }
[Association(QueryExpressionMethod = nameof(GetfffModified), CanBeNull = true)]
public DateTime? xxxModified { get; set; }
public static Expression<Func<Offer, IDataContext, IQueryable<DateTime?>>> GetfffModified()
{
return (obj, db) => db.GetTable<OfferProducts>()
.Where(rel => rel.OfferId == obj.OfferId)
.OrderByDescending(i => i.ModifiedDate)
.Select(x => x.ModifiedDate)
.Take(1);
}
// here I am trying to set max date between ModifiedDate and xxxModified
public DateTime? Modified { get { return ModifiedDate; } set { ModifiedDate = value; } }
In above method I am trying to set the max date between ModifiedDate and xxxModified for Modified values .
Is there any possible to do like that ?

private DateTime? _FinalDate;
public DateTime? FinalDate
{
get
{
if (ModifiedDate < OfferProductsModified)
{
return OfferProductsModified;
}
else
{
return ModifiedDate;
}
}
set
{
if (ModifiedDate < OfferProductsModified)
{
_FinalDate = value;
}
else
{
//DEFAULT Value.
_FinalDate = ModifiedDate;
}
}
}
I found a way

ArgumentNullException when deserializing JSON

I'm trying to deserialize a json like this
{
"geneslist": [
{
"seqid": "NC_045512.2",
"source": "RefSeq",
"type": "region",
"start": "1",
"end": "29903",
"score": ".",
"strand": "+",
"phase": ".",
"attributes": "ID=NC_045512.2:1..29903;Dbxref=taxon:2697049;collectiondate=Dec-2019;country=China;gbacronym=SARS-CoV2;gbkey=Src;genome=genomic;isolate=Wuhan-Hu-1;mol_type=genomic RNA;nathost=Homo sapiens;oldname=Wuhan seafood market pneumonia virus",
"ID": "NC_045512.2:1..29903",
"Note": null,
"Dbxref": "taxon:2697049",
"collectiondate": "Dec-2019",
"country": "China",
"gbacronym": "SARS-CoV2",
"gbkey": "Src",
"gene": null,
"inference": null,
"genome": "genomic",
"isolate": "Wuhan-Hu-1",
"locus_tag": null,
"gene_biotype": null,
"product": null,
"protein_id": null,
"mol_type": "genomic RNA",
"nathost": "Homo sapiens",
"oldname": "Wuhan seafood market pneumonia virus"
},
{
"seqid": "NC_045512.2",
"source": "RefSeq",
"type": "five_prime_UTR",
"start": "1",
"end": "265",
"score": ".",
"strand": "+",
"phase": ".",
"attributes": "ID=id-NC_045512.2:1..265;gbkey=5'UTR",
"ID": "id-NC_045512.2:1..265",
"Note": null,
"function": null,
"Dbxref": null,
"collectiondate": null,
"country;": null,
"gbkey": "5'UTR",
"Dbxrref": null,
"country": null,
"gbacronym": null,
"gene": null,
"inference": null,
"genome": null,
"isolate": null,
"locus_tag": null,
"gene_biotype": null,
"product": null,
"protein_id": null,
"mol_type": null,
"nathost": null,
"oldname": null
},{..} ]
}
where some data might be null or existing, I made two objects for this:
public class GenesList
{
private string seqid;
private string source;
private string type;
private int start;
private int end;
private string score;
private string strand;
private string phase;
private string attributes;
private string ID;
private string Note;
private string function;
private string Dbxref;
private string collectiondate;
private string country;
private string gbacronym;
private string gbkey;
private string gene;
private string inference;
private string genome;
private string isolate;
private string locus_tag;
private string gene_biotype;
private string product;
private string protein_id;
private string mol_type;
private string nathost;
private string oldname;
public string Seqid { get => seqid; set => seqid = value; }
public string Source {get => source; set => source = value; }
public string Type { get => type; set => type = value; }
public int Start { get => start; set => start = value; }
public int End { get => end; set => end = value; }
public string Score { get => score; set => score = value; }
public string Strand { get => strand; set => strand = value; }
public string Phase { get => phase; set => phase = value; }
public string Attributes { get => attributes; set => attributes = value; }
public string ID1 { get => ID; set => ID = value; }
public string Dbxref1 { get => Dbxref; set => Dbxref = value; }
public string Collectiondate { get => collectiondate; set => collectiondate = value; }
public string Country { get => country; set => country = value; }
public string Gbacronym { get => gbacronym; set => gbacronym = value; }
public string Gbkey { get => gbkey; set => gbkey = value; }
public string Genome { get => genome; set => genome = value; }
public string Isolate { get => isolate; set => isolate = value; }
public string Mol_type { get => mol_type; set => mol_type = value; }
public string Nathost { get => nathost; set => nathost = value; }
public string Oldname { get => oldname; set => oldname = value; }
public string Locus_tag { get => locus_tag; set => locus_tag = value; }
public string Gene_biotype { get => gene_biotype; set => gene_biotype = value; }
public string Function { get => function; set => function = value; }
public string Inference { get => inference; set => inference = value; }
public string Product { get => product; set => product = value; }
public string Protein_id { get => protein_id; set => protein_id = value; }
public string GetGene()
{
return gene;
}
public void SetGene(string value)
{
gene = value;
}
}
and
public class GenesWrapper
{
private List<GenesList> geneslist;
public List<GenesList> Genes { get => geneslist; set => geneslist = value; }
}
but when I'm trying to deserialize with
GenesWrapper genesList = new GenesWrapper();
genesList = JsonConvert.DeserializeObject<GenesWrapper>(file2);
I'm getting an ArgomentNullException because the object is null after deserializing, did I build a bad object? At first I tought it could have had some problems with the null values or maybe the order the json file has been made. I used NullValueHandling.Ignore but the values are still null, how can I solve?
Sorry for the wall of text, thank you

This cannot work. Your json is not suitable for creating C# classes. The property "country" occurs two times in your one (the second one) json object.
"country;": null,
"gbkey": "5'UTR",
"Dbxrref": null,
"country": null,
Moreover, visual studio can create the code for you to prevent human errors. Just create the C# code like this, and it will be fine.

you can do this instead :
public class GenesList
{
[JsonProperty("seqid")]
public string Seqid { get; set; }
[JsonProperty("source")]
public string Source { get; set; }
[JsonProperty("type")]
public string Type { get; set; }
[JsonProperty("start")]
[JsonConverter(typeof(ParseStringConverter))]
public int Start { get; set; }
[JsonProperty("end")]
[JsonConverter(typeof(ParseStringConverter))]
public int End { get; set; }
[JsonProperty("score")]
public string Score { get; set; }
[JsonProperty("strand")]
public string Strand { get; set; }
[JsonProperty("phase")]
public string Phase { get; set; }
[JsonProperty("attributes")]
public string Attributes { get; set; }
[JsonProperty("ID")]
public string Id { get; set; }
[JsonProperty("Note")]
public string Note { get; set; }
[JsonProperty("Dbxref")]
public string Dbxref { get; set; }
[JsonProperty("collectiondate")]
public string Collectiondate { get; set; }
[JsonProperty("country")]
public string Country { get; set; }
[JsonProperty("gbacronym")]
public string Gbacronym { get; set; }
[JsonProperty("gbkey")]
public string Gbkey { get; set; }
[JsonProperty("gene")]
public string Gene { get; set; }
[JsonProperty("inference")]
public string Inference { get; set; }
[JsonProperty("genome")]
public string Genome { get; set; }
[JsonProperty("isolate")]
public string Isolate { get; set; }
[JsonProperty("locus_tag")]
public string LocusTag { get; set; }
[JsonProperty("gene_biotype")]
public string GeneBiotype { get; set; }
[JsonProperty("product")]
public string Product { get; set; }
[JsonProperty("protein_id")]
public string ProteinId { get; set; }
[JsonProperty("mol_type")]
public string MolType { get; set; }
[JsonProperty("nathost")]
public string Nathost { get; set; }
[JsonProperty("oldname")]
public string Oldname { get; set; }
}
Then use JObject to navigate to the geneslist, and then just get the string to deserilize it. Something like this :
var jObj = JObject.Parse(json);
var genes = jObj["geneslist"].ToString();
var genesList = JsonConvert.DeserializeObject<List<GenesList>>(genes);
That's if you need to only deserilize geneslist and ignore the rest of the json. If you want to deserilize the whole json keys, you'll need a wrapper class that would define each property in the json root. Something like this :
public class JsonWrapper
{
[JsonProperty("geneslist")]
public IEnumerable<GenesList> Genes { get; set; }
// ... other json keys..
}
Then, you can do this directly :
var genes = JsonConvert.DeserializeObject<JsonWrapper>(json);

ListView Item does not appear to cast correctly

I have in Xamarin.Forms XAML ListView that is being sourced by a typed ItemSource:
ObservableCollection<WorkOrderActivity> serviceList =
new ObservableCollection<WorkOrderActivity>();
servicelistview.ItemsSource = serviceList;
Here is my table:
public class WorkOrderActivity
{
string id;
int workordernumber;
string activity;
string service;
string activitylocation;
float actualquantity;
string reference;
DateTime arrivaltime;
DateTime departuretime;
string remarks;
bool complete;
bool done;
string uom;
int startgauge;
int endgauge;
int contactgauge;
[JsonProperty(PropertyName = "id")]
public string Id
{
get { return id; }
set { id = value; }
}
[JsonProperty(PropertyName = "workordernumber")]
public int WorkOrderNumber
{
get { return workordernumber; }
set { workordernumber = value; }
}
[JsonProperty(PropertyName = "activity")]
public string Activity
{
get { return activity; }
set { activity = value; }
}
[JsonProperty(PropertyName = "service")]
public string Service
{
get { return service; }
set { service = value; }
}
[JsonProperty(PropertyName = "arrivaltime" )]
public DateTime ArrivalTime
{
get { return arrivaltime; }
set { arrivaltime = value; }
}
[JsonProperty(PropertyName = "departuretime")]
public DateTime DepartureTime
{
get { return departuretime; }
set { departuretime = value; }
}
[JsonProperty(PropertyName = "activitylocation")]
public string ActivityLocation
{
get { return activitylocation; }
set { activitylocation = value; }
}
[JsonProperty(PropertyName = "actualquantity")]
public float ActualQuantity
{
get { return actualquantity; }
set { actualquantity = value; }
}
[JsonProperty(PropertyName = "startgauge")]
public int StartGauge
{
get { return startgauge; }
set { startgauge = value; }
}
[JsonProperty(PropertyName = "endgauge")]
public int EndGauge
{
get { return endgauge; }
set { endgauge = value; }
}
[JsonProperty(PropertyName = "contactgauge")]
public int ContactGauge
{
get { return contactgauge; }
set { contactgauge = value; }
}
[JsonProperty(PropertyName = "reference")]
public string Reference
{
get { return reference; }
set { reference = value; }
}
[JsonProperty(PropertyName = "remarks")]
public string Remarks
{
get { return remarks; }
set { remarks = value; }
}
[JsonProperty(PropertyName = "uom")]
public string UOM
{
get { return uom; }
set { uom = value; }
}
[JsonProperty(PropertyName = "done")]
public bool Done
{
get { return done; }
set { done = value; }
}
[JsonProperty(PropertyName = "complete")]
public bool Complete
{
get { return complete; }
set { complete = value; }
}
[Version]
public string Version { get; set; }
[CreatedAt]
public DateTimeOffset CreatedAt { get; set; }
[UpdatedAt]
public DateTimeOffset UpdatedAt { get; set; }
[Deleted]
public bool Deleted { get; set; }
}
The problem occurs when I select an item from the listview, I get the correct record, but the datetime fields only have date in them, the time is zero.
private void servicelistview_ItemTapped(object sender, ItemTappedEventArgs e)
{
var p = (WorkOrderActivity)e.Item;
When I display the record in the listview it comes up with the correct time and date, it just appears that when I cast the selected item as a WorkOrderActivity.
Any ideas?

DateTime.Date returns 00:00:00; from the DateTime.Date documentation:
// Returns:
// A new object with the same date as this instance, and the time value set to 12:00:00
// midnight (00:00:00).
Example:
var dt = new DateTime(2018, 01, 14, 1, 2, 3);
Debug.WriteLine(dt.Date);
Debug.WriteLine(dt.Hour + " " + dt.Minute + " " + dt.Second);
Output:
1/14/2018 12:00:00 AM
1 2 3

Method '{0}' has no supported translation to SQL

I was doing mapping with wildcards. I get this error because the definition of the rule to be searched only comes from a table.
I do not know exactly how right I am doing this here, but as a result I have a mistake and I expect your help.
public class Ekstre
{
private readonly DataClasses1DataContext db = new DataClasses1DataContext();
private readonly KdrGnyClassesDataContext kg = new KdrGnyClassesDataContext();
public bool check { get; set; }
public int Id { get; set; }
public DateTime Tarih { get; set; }
public string Kodu { get; set; }
public string Açıklama { get; set; }
public decimal Tutar { get; set; }
public string bankaKod { get; set; }
private string kod = null;
public string muhKod {
get { return kod = kg.kuralTanimlari
.FirstOrDefault(a => Regex.IsMatch(Açıklama, WildCardToRegular(a.kural))).hesapKodu;
}
set { kod = value; }
}
private string hesap = null;
public string hesapAdi {
get {
hesap = !string.IsNullOrWhiteSpace(muhKod) ? db.MUHHESAP.First(p => p.MUHKOD == muhKod).MUHADI1 : null;
return hesap;
}
set => hesap = value;
}
public string kodTipi { get; set; }
}
public static string WildCardToRegular(string value)
{
return "^" + Regex.Escape(value).Replace("\\?", ".").Replace("\\*", ".*") + "$";
}

You can only use supported functions on dbcontext queries over IQuerable.
You have two options
1. Fire db query by doing ToList() or ToArray() and then .FirstOrDefault(.....)
This has a drawback that it will fetch all records from db and then apply your
function to results.
Convert your filtering function to a simple sql supported function. As far as i know Regex is not supported in entity framework

public string muhKod {
get
{
var firstOrDefault = kg.kuralTanimlari.ToList()
.FirstOrDefault(a => Regex.IsMatch(Açıklama, WildCardToRegular(a.kural)));
if (firstOrDefault != null)
kod = firstOrDefault.hesapKodu;
return kod;
}
set => kod = value;
}
It works so beautifully. Thank you.