can I modify this to better way and fix this error - entity-framework

this is my code
using (var conn = new DataEntities())
{
var query = from c in conn.servers where c.Servername != null select c;
servers srv = query.FirstOrDefault();
if (srv != null)
{
Start.IPAddress = srv.ServerIP;
Start.ServerName = srv.Servername;
Start.GamePort = Convert.ToUInt16(srv.ServerPort);
}
Start.Servers.Add(Start.ServerName, Start.GamePort);
}
servers srv = query.FirstOrDefault(); // error here
An unhandled exception of
type 'System.Data.Entity.Core.EntityCommandExecutionException' occurred in EntityFramework.dll
Additional information: An error occurred while executing the command definition. See the inner exception for details.
can write to usually better way ?
some suggestions i'm still beginner ^^
Thank you

solved
using (var conn = new DataEntities())
{
var query = from c in conn.servers
select new
{
c.Servername,
c.ServerPort,
c.ServerIP
};
foreach (var item in query)
{
Start.IPAddress = item.ServerIP;
Start.ServerName = item.Servername;
Start.GamePort = Convert.ToUInt16(item.ServerPort);
}
Start.Servers.Add(Start.ServerName, Start.GamePort);
}

Related

Accent insensitive in filter backend to datatable in ASP.NET MVC 5

I made a method on the back-end side to handle the filter of my datatable.
On the other hand, this one does not manage the accents of the French language, so if I have "école" and I write "ecole" it cannot find it.
I found this method on another question on stackoverflow
public static String RemoveDiacritics(this String s)
{
String normalizedString = s.Normalize(NormalizationForm.FormD);
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i < normalizedString.Length; i++)
{
Char c = normalizedString[i];
if (CharUnicodeInfo.GetUnicodeCategory(c) != UnicodeCategory.NonSpacingMark)
{
stringBuilder.Append(c);
}
}
return stringBuilder.ToString().Normalize(NormalizationForm.FormC);
}
and it works, but only for part of my problem. It works on the letter or the word that is written in the search, but I am not able to apply it in my linq query, so with the .RemoveDiacritics() method my "école" becomes "ecole", but I don't am not able to apply it in the column of my table and it always looks for "école".
Here the code for the search:
if (search != null)
{
int n;
search = search.Trim();
var isNumeric = int.TryParse(search, out n);
if (isNumeric)
{
IdFilter = n;
query = query.Where(x => x.UsagerId == IdFilter || x.Niveau == IdFilter);
}
else if (search != "")
{
// this line work
textFilter = search.ToLower().RemoveDiacritics();
// This is the full line, but absolutely takes the accents out to get the right information out
// query = query.Where(x => x.Nom.ToLower().Contains(textFilter) || x.Prenom.ToLower().Contains(textFilter) || x.Username.ToLower().Contains(textFilter) || x.Email.ToLower().Contains(textFilter) || x.EtabNom.ToLower().Contains(textFilter) || x.ActifStatut.ToLower().Contains(textFilter));
// This is the line that will replace the line above, which I try and it doesn't work ( this part: x.Prenom.ToLower().RemoveDiacritics())
query = query.Where(x => x.Prenom.ToLower().RemoveDiacritics().Contains(textFilter));
}
}
This is the basic query:
IQueryable<ListeUsagers> query = (from u in db.USAGERs
join e in db.ETABLISSEMENTs on u.USAGER_INST equals e.ETAB_CODE
where u.USAGER_INST == instId && u.USAGER_NIVEAU > 3 && u.USAGER_NIVEAU < 5 //&& u.USAGER_ACTIF == 1
select new ListeUsagers()
{
UsagerId = u.USAGER_id,
Nom = u.USAGER_NOM,
Prenom = u.USAGER_PRENOM,
EtabCode = e.ETAB_CODE,
EtabNom = e.ETAB_NOM_COURT,
EtabType = e.ETAB_TYPE,
Niveau = u.USAGER_NIVEAU,
Username = u.USAGER_USERNAME,
UserPassword = u.USAGER_MP,
DateCreation = u.USAGER_DATE_INSC,
Sexe = u.USAGER_SEXE,
Lang = u.USAGER_LANGUE,
Telephone = u.USAGER_TELEPHONE,
Email = u.USAGER_EMAIL,
FonctionTravail = u.USAGER_FONCTION,
LieuTravail = u.USAGER_LIEUTRAVAIL,
Note = u.USAGER_NOTE,
Actif = u.USAGER_ACTIF,
ActifStatut = u.USAGER_ACTIF == 0 ? "Inactif" : "Actif"
});
This is the error:
LINQ to Entities does not recognize the method 'System.String RemoveDiacritics(System.String)' method, and this method cannot be translated into a store expression.
There's built-in functionality to do this in entityframework: https://learn.microsoft.com/en-us/ef/core/miscellaneous/collations-and-case-sensitivity if you're using EF 5+
You'll want an accent insensitive collation ("AI", not "AS" in the examples on that page.)

Entities may have been modified or deleted since entities were loaded. Error during transaction

During the execution of the following piece of code, I get the message
Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.
And there are loads of occurrences of that in here, but I didn't find a solution to my problem.
This only happens to me because I'm running _db.SaveChanges() two times inside one transaction (_db is my database context object), and I HAVE to do so because I need the generated ID that it gives me in order to proceed with the code.
If anyone can help me, I'd appreciate it. Also, if you know a way to proceed without the two _db.SaveChanges() or with a different way of approaching the transaction, I welcome you to show it.
using (var trans = _db.Database.BeginTransaction())
{
try
{
var f = cbxFornecedor.SelectedItem as Fornecedor;
var c = new Compra
{
CompraId = compra.CompraId,
DataCompra = dtpDataCompra.Value,
ListaProdutos = new List<ListaProdutos>(),
Fornecedor = f,
Referencia = tbxReferencia.Text,
Situacao = rbtEntregue.Checked
};
_db.Compras.Add(c);
_db.SaveChanges();
foreach (var cada in _itens)
c.ListaProdutos.Add(new ListaProdutos
{
Compra = c,
CompraId = c.CompraId,
Produto = cada.ProdutoClasse,
ProdutoId = cada.ProdutoClasse.ProdutoId,
Valor = cada.ValorTotal,
Quantidade = cada.Quantidade,
});
foreach (var cada in c.ListaProdutos)
if (_db.ListaProdutos.Find(cada.CompraId, cada.ProdutoId) != null)
_db.Entry(cada).State = EntityState.Modified;
else
_db.ListaProdutos.Add(cada);
_db.Entry(c).State = EntityState.Modified;
_db.SaveChanges();
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
MessageBox.Show(this, ex.Message, #"Erro", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
And, just to be clear, I know that my problem is with that fact that the transaction is there. I tried removing it and it worked. Also, if I take out the second _db.SaveChanges(), it works too.
The exception is only thrown in the second _db.SaveChanges(), and only if it is surrounded by the transaction block.
It is not direct answer to your question, but it may be helpful.
You do not need to specify Compra and CompraId for new ListaProdutos because EF smart enough to figure it out. Also it looks like that you do not need _db.ListaProdutos.Find(cada.CompraId, cada.ProdutoId) != null check because cada.CompraId - is new Id and it can not be in DB at this moment. Also you do not need _db.ListaProdutos.Add(cada); because EF already new that you are adding this records. Can you try next code?
var f = cbxFornecedor.SelectedItem as Fornecedor;
var c = new Compra
{
DataCompra = dtpDataCompra.Value,
ListaProdutos = new List<ListaProdutos>(),
Fornecedor = f,
Referencia = tbxReferencia.Text,
Situacao = rbtEntregue.Checked
};
_db.Compras.Add(c);
foreach (var cada in _itens)
c.ListaProdutos.Add(new ListaProdutos
{
Produto = cada.ProdutoClasse,
ProdutoId = cada.ProdutoClasse.ProdutoId,
Valor = cada.ValorTotal,
Quantidade = cada.Quantidade,
});
_db.SaveChanges();

IQueryable in foreach - open DataReader error

When i run this code
public PartialViewResult GetHardware()
{
IQueryable<Hardware> hardware = db.Hardwares;
HardwareState hwState = new HardwareState();
IQueryable<IGrouping<string, Hardware>> groupByCategory = hardware.GroupBy(g => g.Category);
foreach (IGrouping<string, Hardware> group in groupByCategory)
{
hwState.GroupName = group.Key;
hwState.GroupUnitsCount = group.Count();
hwState.StorageReservedCount
= group.Where(m =>
m.Place.IsStorage == true &&
m.PlaceID != (int)Constants.HardwareState.Created &&
m.HardwareState == (int)Constants.HardwareState.Reserved).Count();
}
return PartialView(hwState);
}
I get an error about that the navigation property m.Place = null
when i transfer some of the text with the code of the foreach block
public PartialViewResult GetHardware()
{
IQueryable<Hardware> hardware = db.Hardwares;
HardwareState hwState = new HardwareState();
IQueryable<IGrouping<string, Hardware>> groupByCategory = hardware.GroupBy(g => g.Category);
hwState.StorageReservedCount
= hardware.Where(m =>
m.Place.IsStorage == true &&
m.PlaceID != (int)Constants.HardwareState.Created &&
m.HardwareState == (int)Constants.HardwareState.Reserved).Count();
foreach (IGrouping<string, Hardware> group in groupByCategory)
{
hwState.GroupName = group.Key;
hwState.GroupUnitsCount = group.Count();
}
return PartialView(hwState);
}
,the navigation property is not set to null and the error does not appear
Extension methods such as .AsQueryable or Include(x => x.Place) do not help me
How can i solve this problem?
UPDATE: If i change the type to IEnumerable instead IQueryable it begins to work!
but i would like to work with the IQueryable type
UPDATE2: I'm sorry, i did not put it correctly when i wrote that the error is an empty navigation property. Error that appears in fact
"There is already an open DataReader associated with this Command which must be closed first."
As described in this answer it is because: (quote)
"Another scenario when this always happens is when you iterate through
result of the query (IQueryable) and you will trigger lazy loading for
loaded entity inside the iteration."
But it does not say how to solve the problem without using ToList () or MARS

how to debug EF 5 null reference exception?

I am getting a null refrence exception when im filtering EF but I am absolultely clueless.
public IEnumerable<TonalityBatchModel> GetTonalityBatch(int briefID)
{
try
{
var brief = NeptuneUnitOfWork.Briefs.FindWhere(b => b.ID == briefID).FirstOrDefault();
if (brief != null && brief.TonalityCriteria != null)
{
return brief.TonalityCriteria.TonalityBatches
.Select(b => new TonalityBatchModel()
{
BriefID = b.BriefID,
Status = b.TonalityCriteria.IsActive == true ?"Active":"Ended",
BatchID = b.ID,
CompetitorID = b.BriefCompetitorID,
Competitor = brief.BriefCompetitors.Where(i=>i.ID == b.BriefCompetitorID).Select(c=>c.Organisation.Name).First(),
Size = b.BatchSize,
StartDate = b.StartDate,
EndDate = b.EndDate,
IsPublished = b.Lookup_TonalityBatchStatus.ID == (int)TonalityBatchStatus.Published?"Yes":"No",
IsCompleted = b.Lookup_TonalityBatchStatus.ID == (int)TonalityBatchStatus.Completed ? "Yes" : "No",
IsAssigned = b.Lookup_TonalityBatchStatus.ID == (int)TonalityBatchStatus.Allocated ? "Yes" : "No",
ImportantCount = b.TonalityItems.Count(i=> i.IsImportant),
ArticlesCount = b.TonalityItems.Count,
FavourableCount = b.TonalityItems.Count(i => i.Lookup_TonalityScoreTypes.ID ==(int)TonalitySourceType.Favourable),
UnfavourableCount = b.TonalityItems.Count(i => i.Lookup_TonalityScoreTypes.ID ==(int)TonalitySourceType.Unfavourable),
NeutralCount = b.TonalityItems.Count(i => i.Lookup_TonalityScoreTypes.ID ==(int)TonalitySourceType.Neutral)
}).ToList();
}
return new List<TonalityBatchModel>();
}
catch (Exception ex)
{
Logger.Error(ex);
throw;
}
}
You'll need to reduce your query to a simpler query, and then start building it back up again until the NullReferenceException occurs. Looking at your code, here are some likely places (I'm making some assumptions since I don't know everything about your model):
Competitor = brief.BriefCompetitors.Where(i=>i.ID == b.BriefCompetitorID).Select(c=>c.Organisation.Name).First()
BriefCompetitors could be null. c.Organisation could be null.
IsPublished = b.Lookup_TonalityBatchStatus.ID == (int)TonalityBatchStatus.Published?"Yes":"No",
(and other similar lines) b.Lookup_TonalityBatchStatus might be null.
ImportantCount = b.TonalityItems.Count(i=> i.IsImportant),
(and other similar lines) b.TonalityItems might be null.
I believe this is because your count is returning null records. I could be wrong but the SQL that's being produced here is something like:
INNER JOIN TonalityItems i on i.Lookup_TonalityScoreTypes == x
Where x is the value of (int)TonalitySourceType.Favourable. Because this join has no matching results there is nothing to do a count on. You could try adding ?? 0 to the end of the query:
FavourableCount = b.TonalityItems.Count(i => i.Lookup_TonalityScoreTypes.ID ==(int)TonalitySourceType.Favourable) ?? 0,

Error: The entity or complex type cannot be constructed in a LINQ to Entities query ASP.NET MVC3

Good day to all.
Im Having Entity or complex type cannot be encountered This is the first time i encountered this type of error Someone Help me
public IEnumerable<APPLICANT> GetApplicant()
{
IEnumerable<APPLICANT> applicantdata = Cache.Get("applicants") as IEnumerable<APPLICANT>;
IEnumerable<Profile> profiledata = Cache.Get("profiles") as IEnumerable<Profile>;
if (applicantdata == null)
{
var applicantList = (from a in context.Profiles
join app in context.APPLICANTs
on a.PROFILE_ID equals app.Profile_id
where app.APPLICANT_LogicalDelete == false
select new APPLICANT()
{
APPLICANT_LastName = a.Applicant_LASTNAME,
APPLICANT_FirstName = a.Applicant_FIRSTNAME,
APPLICANT_MiddleName = a.Applicant_MIDDLENAME,
APPLICANT_Address = a.Applicant_ADDRESS,
APPLICANT_City = a.Applicant_CITY,
APPLICANT_Phone = a.Applicant_PHONE,
APPLICANT_Email= a.Applicant_EMAIL
});
applicantdata = applicantList.Where(v => !String.IsNullOrEmpty(v.APPLICANT_LastName)).OrderBy(v => v.APPLICANT_ID).ToList();
if (applicantdata.Any())
{
Cache.Set("applicants", applicantdata, 30);
}
}
return applicantdata.ToList().Take(1000);
}
And This is the line where i encounter the error Thanks!
applicantdata = applicantList.Where(v => !String.IsNullOrEmpty(v.APPLICANT_LastName)).OrderBy(v => v.APPLICANT_ID).ToList();
AND THE ERROR IN THE LINE ABOVE IS
System.NotSupportedException: The entity or complex type 'Model.APPLICANT' cannot be constructed in a LINQ to Entities query.
It looks to me that your query is constructing objects of type registerd as entity type. You don't need to initalize such objects with select new{...}.
Try to change your query like this:
var applicantList = (from a in context.Profiles
join app in context.APPLICANTs
on a.PROFILE_ID equals app.Profile_id
where app.APPLICANT_LogicalDelete == false
select app
);
..........