I have this method
Meeting is a class
Attendees is an ICollection in Meeting
Class
public partial class Meeting
{
public Meeting()
{
this.Attendees = new List<Attendees>();
}
public virtual ICollection<Attendees> Attendees{ get; set; }
[...]
Method Controller
private void RemoveRowsDuplicated(Meeting model)
{
if (model.Attendees != null)
{
foreach (var item in model.Attendees.GroupBy(x => x.UserName).Select(y => y.Last()))
{
context.Attendees.Remove(item);
}
}
}
The objective is remove duplicate Attendees with the same username in the table.
But the current method it deletes all records and keeps the duplicate
Where am I going wrong?
Correct version of your method will look like this:
private static void RemoveRowsDuplicated(Meeting model)
{
if (model.Attendees != null)
{
var duplicates = new List<Attendees>();
foreach (var item in model.Attendees.GroupBy(x => x.UserName).Where(x=>x.Count()>1))
{
duplicates.AddRange(item.Skip(1));
}
duplicates.ForEach(x=>context.Attendees.Remove(x));
}
}
You can try writing raw SQL and invoking via EF and return Attendees objects in a list.
var query = "Select * from Attendees group by username";
var attendeesList = dbContext.Database.SqlQuery<Attendees>(query).ToList<Attendees>();
As I can see you grouped elements by name and remove last item. So you remove unique elements.
Like this
private void RemoveRowsDuplicated(Meeting model)
{
if (model.Attendees != null)
{
var temporaryAtendees = new List<Attendees>();
foreach(var item in model.Attendees)
{
if (temporaryAtendees.Contains(item))
{
context.Attendees.Remove(item);
}
else
{
temporaryAtendees.Add(item);
}
}
}
}
Related
I have a razor view in ASP.NET MVC looping over an array of objects from my model and generating corresponding html controls.
My html elements are properly bound, except my drop down lists who can't seem to select the value provided to them by the model.
My view: (in the hereby case, I'm simply displaying a list of countries)
#for (var i = 0; i < Model.answers.Count(); i++)
{
<div class="form-group">
...
#switch (Model.answers[i].Statement.QuestionType)
{
...
case ExternalEnums.QuestionTypeEnum.country:
#Html.DropDownListFor(Model => Model.answers[i].Value,
new SelectList(Model.Pays, "Value", "Text"))
break;
}
...
</div>
}
My view controller, generating the country list items and retrieving the existing model entries:
public class HomeIndexViewModel
{
private QuestionsModelContainer dbContext;
private AdmcommonEntities admCommonContext;
...
public List<Answer> answers { get; private set; }
private IEnumerable<SelectListItem> _countries;
public IEnumerable<SelectListItem> Pays
{
get
{
if (_countries == null)
SetCountries();
return _countries;
}
}
public HomeIndexViewModel()
{
Init(-1, null);
}
public HomeIndexViewModel(int page, string _pageWideError = null)
{
Init(page, _pageWideError);
}
private void Init(int page, string _pageWideError = null)
{
dbContext = new QuestionsModelContainer();
PageNum = page;
pageWideError = _pageWideError;
answers = GetAnswers();
...
}
private void SetCountries()
{
using (admCommonContext = new AdmcommonEntities())
{
var localEntities = admCommonContext.Pays.ToList();
var localList = new List<SelectListItem>();
localList.Add(new SelectListItem());
foreach (var item in localEntities)
{
var newItemList = new SelectListItem();
newItemList.Text = item.Libelle;
newItemList.Value = item.Libelle;
localList.Add(newItemList);
}
_countries = localList;
}
}
public List<Statement> GetStatements()
{
var statements = dbContext.StatementSet.Where(w => w.Page == PageNum).OrderBy(w => w.Order).ToList();
return statements;
}
public List<Answer> GetAnswers()
{
var statements = GetStatements();
var ExistingAnswers = new List<Answer>();
if (AdminPermissionManager.IsUserAuthenticated()) //Loading existing entries.
ExistingAnswers = Answer.GetExistingAnswers(statements, dbContext);
var answers = new List<Answer>();
foreach (var item in statements)
{
var answer = ExistingAnswers.Where(w => w.StatementId == item.Id).FirstOrDefault();
if (answer == null)
{
answer = new Answer();
answer.StatementId = item.Id;
answer.Statement = item;
}
answers.Add(answer);
}
return answers;
}
}
My model class, simply containing the value I'm trying to display:
[MetadataType(typeof(AnswerMetaData))]
public partial class Answer
{
...
public static List<Answer> GetExistingAnswers(List<int> statementIds, QuestionsModelContainer dbContext)
{
List<Answer> ExistingAnswers;
var usercode = AdminPermissionManager.GetUserCode();
ExistingAnswers = dbContext.AnswerSet.Where(w => statementIds.Contains(w.StatementId) && w.ChildCode == usercode).ToList();
return ExistingAnswers;
}
public static List<Answer> GetExistingAnswers(List<Statement> statements, QuestionsModelContainer dbContext)
{
var statementIds = statements.Select(w => w.Id).ToList();
return GetExistingAnswers(statementIds, dbContext);
}
}
public class AnswerMetaData
{
[InternalValidation]
public string Value { get; set; }
private class InternalValidationAttribute : ValidationAttribute
{
...
}
}
I'm sure there's something very obvious that I'm missing, but can't figure out what exactly :/...
You're nearly there actually, this part in the View:
#Html.DropDownListFor(
Model => Model.answers[i].Value,
new SelectList(Model.Pays, "Value", "Text")
)
You create a new selectlist - each time, but you already have a IEnumerable<SelectListItem> created, so you don't have to recreate that list. The only thing you might be missing (most likely) is the "Selected" item option.
If you already have a value selected (and it isn't the first one) it will not be selected dropdown option - also because you pass the value of the selected option as the "ID" of the field (not the actual value) - DropDownListFor is kinda weird in that regard.
So you want to change your #Html.DropDownListFor to something like this:
#Html.DropDownListFor(
Model => Model.answers[i].Name,
Pays(Model.answers[i].Value)
)
When that being done you should change your property "Pays" in the ViewModel to a method that accepts a value (idk what you're using, but let's assume it's string) - to something along the lines of this:
public IEnumerable<SelectListItem> Pays(string selectedValue)
{
if (_countries == null) SetCountries();
var value = new List<SelectListItem>();
foreach(var item in _countries)
{
item.Selected = (item.Value == selectedValue);
value.Add(item);
}
return value;
}
This above is a bit pseudocoded since I'm typing this from memory, but it should get you into the correct direction. Also remember to check with the inspect element in the browser if the dropdown HTML element really has the correct name attribute.
Trying to use Except to exclude items from a list. However the following code is not working for me i.e. my list still includes the records that it should exclude. Is there anything obvious that I am doing wrong? Is there an issue with my loops? BTW the inverse of this code works i.e correct record is inserted when RunTime matches.
[HttpPost]
public JsonResult InsertActivities([FromBody] List<MemberData> customers)
{
var mData =_context.MemberData.Select(x => x.RunTime).ToList();
foreach (var item in mData)
{
var exclude = customers.Where(x => x.RunTime == item).ToList();
var list = customers.Except(exclude).ToList();
foreach (var data in list)
{
_context.MemberData.Add(data);
}
}
int insertedRecords = _context.SaveChanges();
return Json(insertedRecords);
}
Firstly be sure you have model design like below:
public class MemberData:IEquatable<MemberData>
{
public int Id { get; set; }
public string RunTime { get; set; }
public bool Equals(MemberData other)
{
if (other is null)
return false;
return this.RunTime == other.RunTime;
}
public override bool Equals(object obj) => Equals(obj as MemberData);
public override int GetHashCode() => (RunTime).GetHashCode();
}
Then change your code like below:
public JsonResult InsertActivities([FromBody] List<MemberData> customers)
{
//hard-coded the value...
//customers = new List<MemberData>()
//{
// new MemberData(){RunTime="aa"},
// new MemberData(){RunTime="bb"},
// new MemberData(){RunTime="ee"},
//}; //hard-coded the value...
var mData = _context.MemberData.ToList();
var list = customers.Except(mData);
foreach (var item in list)
{
foreach (var data in list)
{
_context.MemberData.Add(data);
}
}
int insertedRecords = _context.SaveChanges();
return Json(insertedRecords);
}
Note:
For inserting data to database successfully, if your model contains primary key, be sure the data's(after did Except operation) keys are not duplicated with the existing database data. Or you can just do like what I did in above code that do not set value for primary key.
I have the following list of strings :
var files = new List<string> {"file0","file1","file2","file3" };
I would like to be able to add new files to this list, but if the inserted file is present in the list, I would like to insert custom value that will respect the following format $"{StringToBeInserted}"("{SomeCounter}
For instance : try to add "file0" and "file0" is already I would like to insert "file0(1)". If I try again to add "file0" ... I would like to insert with "file0(2)" and so on ... Also, I would like to provide a consistency, for instance if I delete "file0(1)" ... and try to add again "item0" ... I expect that "item0(1)" to be added. Can someone help me with a generic algorithm ?
I would use a HashSet<string> in this case:
var files = new HashSet<string> { "file0", "file1", "file2", "file3" };
string originalFile = "file0";
string file = originalFile;
int counter = 0;
while (!files.Add(file))
{
file = $"{originalFile}({++counter})";
}
If you have to use a list and the result should also be one, you can still use my set approach. Just initialize it with your list and the result list you'll get with files.ToList().
Well, you should create your own custom class for it, using the data structure you described and a simple class that includes a counter and an output method.
void Main()
{
var items = new ItemCountList();
items.AddItem("item0");
items.AddItem("item1");
items.AddItem("item2");
items.AddItem("item0");
items.ShowItems();
}
public class ItemCountList {
private List<SimpleItem> itemList;
public ItemCountList() {
itemList = new List<SimpleItem>();
}
public void DeleteItem(string value) {
var item = itemList.FirstOrDefault(b => b.Value == value);
if (item != null) {
item.Count--;
if (item.Count == 0)
itemList.Remove(item);
}
}
public void AddItem(string value) {
var item = itemList.FirstOrDefault(b => b.Value == value);
if (item != null)
item.Count++;
else
itemList.Add(new SimpleItem {
Value = value,
Count = 1
});
}
public void ShowItems() {
foreach (var a in itemList) {
Console.WriteLine(a.Value + "(" + a.Count + ")");
}
}
}
public class SimpleItem {
public int Count {get; set;}
public string Value {get; set;}
}
I have stumbled upon a problem with Entity Framework this morning.
I have following code mapping a modified entity and saving it into database.
public Group Save(Group x)
{
using (var db = new HostContext())
{
db.Projects.Attach(x.Project);
if (x.ID != 0)
{
db.AttachableObjects.Attach(x);
var manager = ((IObjectContextAdapter)db).ObjectContext.ObjectStateManager;
manager.ChangeObjectState(x, EntityState.Modified);
}
else
{
db.AttachableObjects.Add(x);
}
db.SaveChanges();
return x;
}
}
I call Save method with existing group as a parameter. Group contains one user I want to add as a member.
The method finishes successfully, however the relationship is not persisted in database.
Any help is very appreciated.
EDIT: These are my classes
class User : AttachableObject
{
...
private List<Group> memberof;
[DataMember]
[InverseProperty("Members")]
public List<Group> MemberOf
{
get { return memberof; }
set { memberof = value; }
}
...
}
class Group : AttachableObject
{
...
private List<User> members;
[DataMember]
[InverseProperty("MemberOf")]
public List<User> Members
{
get { return members; }
set { members = value; }
}
...
}
EDIT2: This is where the Save method is called
public Group AcceptInvite(int id)
{
var mapper = new InviteMapper();
var userMapper = new UserMapper();
var groupMapper = new GroupMapper();
var invite = mapper.Find(id);
if (invite != null)
{
var group = groupMapper.Find(invite.GroupID);
var user = userMapper.Find(invite.InviteeID);
group.Members.Add(user);
mapper.Delete(invite.ID);
return groupMapper.Save(group);
}
return null;
}
EDIT3: My mappers
public class GroupMapper
{
public Group Find(int id)
{
using (var db = new HostContext())
{
return db.AttachableObjects
.Include("Project")
.OfType<Group>().FirstOrDefault(x => x.ID == id);
}
}
}
The rest of the mappers is the same, only using their own tables.
You are not changing the relationship info of Project, you are only setting x to modified, relationship info must be changed explicitly.
So x.Project must have some property that points back to Group, you need to set it so the change is recorded.
I am guessing that x is resurrected via some deserialization process?
I am trying to find out how to do paging in SS.Redis, I use:
var todos = RedisManager.ExecAs<Todo>(r => r.GetLatestFromRecentsList(skip,take));
it returns 0, but i am sure the database is not empty, because r.GetAll() returns a list of things. What is the correct way to do this?
EDIT: Here is the code:
public class ToDoRepository : IToDoRepository
{
public IRedisClientsManager RedisManager { get; set; } //Injected by IOC
public Todo GetById(long id) {
return RedisManager.ExecAs<Todo>(r => r.GetById(id));
}
public IList<Todo> GetAll() {
return RedisManager.ExecAs<Todo>(r => r.GetAll());
}
public IList<Todo> GetAll(int from, int to) {
var todos = RedisManager.ExecAs<Todo>(r => r.GetLatestFromRecentsList(from,to));
return todos;
}
public Todo NewOrUpdate(Todo todo) {
RedisManager.ExecAs<Todo>(r =>
{
if (todo.Id == default(long)) todo.Id = r.GetNextSequence(); //Get next id for new todos
r.Store(todo); //save new or update
});
return todo;
}
public void DeleteById(long id) {
RedisManager.ExecAs<Todo>(r => r.DeleteById(id));
}
public void DeleteAll() {
RedisManager.ExecAs<Todo>(r => r.DeleteAll());
}
}
As I don't see any code, I'm assuming you're not maintaining the Recents list when you're adding the entites. Here's the test case for GetLatestFromRecentsList:
var redisAnswers = Redis.As<Answer>();
redisAnswers.StoreAll(q1Answers);
q1Answers.ForEach(redisAnswers.AddToRecentsList); //Adds to the Recents List
var latest3Answers = redisAnswers.GetLatestFromRecentsList(0, 3);
var i = q1Answers.Count;
var expectedAnswers = new List<Answer>
{
q1Answers[--i], q1Answers[--i], q1Answers[--i],
};
Assert.That(expectedAnswers.EquivalentTo(latest3Answers));
Redis StackOverflow is another example that uses the Recents list feature to show the latest Questions added. It maintains the recent list of questions by calling AddToRecentsList whenever a new Question is created.