We Keep Coding

How to add distinct value in database using Entity Framework

IEnumerable<WebsiteWebPage> data = GetWebPages();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
db.WebsiteWebPages.Add(pagesinfo);
}
}
db.SaveChanges();
I want to add only distinct values to database in above code. Kindly help me how to do it as I am not able to find any solution.

IEnumerable<WebsiteWebPage> data = GetWebPages();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
var a = db.WebsiteWebPages.Where(i => i.WebPage == value.WebPage.ToString()).ToList();
if (a.Count == 0)
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
db.WebsiteWebPages.Add(pagesinfo);
db.SaveChanges();
}
}
}
This is the code that I used to add distinct data.I hope it helps

In addition to the code sample Furkan Öztürk supplied, Make sure your DB has a constraint so that you cannot enter duplicate values in the column. Belt and braces approach.

I assume that by "distinct values" you mean "distinct value.WebPage values":
// get existing values (if you ever need this)
var existingWebPages = db.WebsiteWebPages.Select(v => v.WebPage);
// get your pages
var webPages = GetWebPages().Where(v => v.WebPage.Contains(".htm"));
// get distinct WebPage values except existing ones
var distinctWebPages = webPages.Select(v => v.WebPage).Distinct().Except(existingWebPages);
// create WebsiteWebPage objects
var websiteWebPages = distinctWebPages.Select(v =>
new WebsiteWebPage { WebPage = v, WebsiteId = websiteid});
// save all at once
db.WebsiteWebPages.AddRange(websiteWebPages);
db.SaveChanges();

Assuming that you need them to be unique by WebPage and WebSiteId
IEnumerable<WebsiteWebPage> data = GetWebPages();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
if (db.WebsiteWebPages.All(c=>c.WebPage != value.WebPage|| c.WebsiteId != websiteid))
{
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
db.WebsiteWebPages.Add(pagesinfo);
}
}
}
db.SaveChanges();
UPDATE
To optimize this (given that your table contains much more data than your current list), override your equals in WebsiteWebPage class to define your uniqueness criteria then:
var myWebsiteWebPages = data.select(x=> new WebsiteWebPage { WebPage = x.WebPage, WebsiteId = websiteid}).Distinct();
var duplicates = db.WebsiteWebPages.Where(x=> myWebsiteWebPage.Contains(x));
db.WebsiteWebPages.AddRange(myWebsiteWebPages.Where(x=> !duplicates.Contains(x)));
this is a one database query to retrieve ONLY duplicates and then removing them from the list

You can use the following code,
IEnumerable<WebsiteWebPage> data = GetWebPages();
var templist = new List<WebsiteWebPage>();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
templist.Add(pagesinfo);
}
}
var distinctList = templist.GroupBy(x => x.WebsiteId).Select(group => group.First()).ToList();
db.WebsiteWebPages.AddRange(distinctList);
db.SaveChanges();
Or you can use MoreLINQ here to filter distinct the list by parameter like,
var res = tempList.Distinct(x=>x.WebsiteId).ToList();
db.WebsiteWebPages.AddRange(res);
db.SaveChanges();

Compare Two Complex List of data

When I am Trying to save current list of data into database, I need to get already existing data from database, and need to compare with current list of data.
I have two lists one is PreviousList(existing data from DB) and other is CurrentList(Modified data)
public class SoftClose
{
public int ID = -1;
public int AID = -1;
public int WFID = -1;
public string PREFIX;
public DateTime SCDATE;
public string STATUS;
}
In CurrentList I modified Prefix to D2 where ID=1 and added new row(Id=4)...
My req is
When I am trying to save CurrentList to Db,
If there is any new Prefix in CurrentList that is not there in PreviousList I need to insert that new row and need to change Status to ADD for that row.
I changed Prefix to D2 where Id = 1 in CurrentList. D1 is there is DB and but not in CurrentList so i need to delete it. So i need to change the status to DELETE for that record. I should not insert D2 record where id=1 becuase D2 is already there. If I changed to D5 where Id = 1 then I need to insert it because D5 is not there in DB So i need to change the status to UPDATE.
How to do this? What is the best approach to compare lists

here is a solution you could try:
List<SoftClose> previousList = new List<SoftClose>(){
new SoftClose(){ID=1, Status = "NO_CHANGE",AID="19", Prefix = "D1"},
new SoftClose(){ID=2, Status = "NO_CHANGE",AID="20", Prefix = "D2"},
new SoftClose(){ID=3, Status = "NO_CHANGE",AID="21", Prefix = "D3"}
};
List<SoftClose> currentList = new List<SoftClose>(){
new SoftClose(){ID=1, Status = "NO_CHANGE",AID="19", Prefix = "D2"},
new SoftClose(){ID=2, Status = "NO_CHANGE",AID="20", Prefix = "D2"},
new SoftClose(){ID=3, Status = "NO_CHANGE",AID="21", Prefix = "D6"},
new SoftClose(){ID=4, Status = "NO_CHANGE",AID="22", Prefix = "D4"},
new SoftClose(){ID=5, Status = "NO_CHANGE",AID="22", Prefix = "D5"}
};
var addlist = currentList.Where(c => previousList.All(p => !p.ID.Equals(c.ID) && !p.Prefix.Equals(c.Prefix)));
foreach(var n in addlist)
{
var index = currentList.FindIndex(p => p.Prefix.Equals(n.Prefix));
currentList[index].Status = "ADD";
}
var updateORdeletelist = currentList.Where(c => c.Status.Equals("NO_CHANGE") && previousList.Exists(p => p.ID.Equals(c.ID) && !p.Prefix.Equals(c.Prefix)));
foreach (var n in updateORdeletelist)
{
var index = currentList.FindIndex(p => p.Prefix.Equals(n.Prefix));
if (previousList.FindIndex(p => p.Prefix.Equals(n.Prefix)) < 0)
currentList[index].Status = "UPDATE";
else
currentList[index].Status = "DELETE";
}
foreach (var item in currentList)
{
Console.WriteLine($"Id:{item.ID}, Desc1:{item.Prefix}, Status:{item.Status}");
}
output
Id:1, Desc1:D2, Status:DELETE
Id:2, Desc1:D2, Status:NO_CHANGE
Id:3, Desc1:D6, Status:UPDATE
Id:4, Desc1:D4, Status:ADD
Id:5, Desc1:D5, Status:ADD

There is a tool called Side by Side SQL Comparer in C# at https://www.codeproject.com/Articles/27122/Side-by-Side-SQL-Comparer-in-C.
basic use of the component:
using (TextReader tr = new StreamReader(#"c:\1.sql"))
{
sideBySideRichTextBox1.LeftText = tr.ReadToEnd();
}
using (TextReader tr = new StreamReader(#"c:\2.sql"))
{
sideBySideRichTextBox1.RightText = tr.ReadToEnd();
}
sideBySideRichTextBox1.CompareText();
You load the left and right sides to their respective variables sideBySideRichTextBox1.LeftText and sideBySideRichTextBox1.RightText and compare them with sideBySideRichTextBox1.CompareText();
In your case the 1.sql and 2.sql would be your PreviousList and CurrentList -database files.
There is more detailed documentation at the project-site.

Listing in WCF Entity

I have a problem with LINQ query (see comment) there is a First method and it only shows me the first element.
When I write in the console "Sales Representative" it shows me only the first element of it as in
I would like to get all of data about Sales Representative. How can I do it?
public PracownikDane GetPracownik(string imie)
{
PracownikDane pracownikDane = null;
using (NORTHWNDEntities database = new NORTHWNDEntities())
{
//Employee matchingProduct = database.Employees.First(p => p.Title == imie);
var query = from pros in database.Employees
where pros.Title == imie
select pros;
// Here
Employee pp = query.First();
pracownikDane = new PracownikDane();
pracownikDane.Tytul = pp.Title;
pracownikDane.Imie = pp.FirstName;
pracownikDane.Nazwisko = pp.LastName;
pracownikDane.Kraj = pp.Country;
pracownikDane.Miasto = pp.City;
pracownikDane.Adres = pp.Address;
pracownikDane.Telefon = pp.HomePhone;
pracownikDane.WWW = pp.PhotoPath;
}
return pracownikDane;
}

Right now you are just getting the .First() result from the Query collection:
Employee pp = query.First();
If you want to list all employees you need to iterate through the entire collection.
Now, if you want to return all the employee's you should then store each new "pracownikDane" you create in some sort of IEnumerable
public IEnumerable<PracownikDane> GetPracownik(string imie) {
using (NORTHWNDEntities database = new NORTHWNDEntities())
{
var query = from pros in database.Employees
where pros.Title == imie
select pros;
var EmployeeList = new IEnumerable<PracownikDane>();
foreach(var pp in query)
{
EmployeeList.Add(new PracownikDane()
{
Tytul = pp.Title,
Imie = pp.FirstName,
Nazwisko = pp.LastName,
Kraj = pp.Country,
Miasto = pp.City,
Adres = pp.Address,
Telefon = pp.HomePhone,
WWW = pp.PhotoPath
});
}
return EmployeeList;
}
Then, with this returned List you can then do what ever you wanted with them.

How to avoid repeating when I get data from stored procedure?

I get a list from stored procedure with its child date I want to avoid repeating when I add items to the the list
Here is my code:
var cmd = db.Database.Connection.CreateCommand();
cmd.CommandText = "[dbo].[T]";
db.Database.Connection.Open();
var reader1 = cmd.ExecuteReader();
var objectContext1 = ((IObjectContextAdapter)db).ObjectContext;
var usersLi = objectContext1.Translate<GetAllNewsForUser>(reader1).ToList();
List<GetAllNewsForUser> lll = new List<GetAllNewsForUser>();
foreach (var item in usersLi)
{
NewsInfo newsInfo = new NewsInfo();
GetAllNewsForUser g = new GetAllNewsForUser();
g.UserName = item.UserName;
NewsInfo nnn = new NewsInfo();
nnn.NewsTitle = item.NewsTitle;
nnn.NewsId = item.NewsId;
g.NewsInfos.Add(nnn);
lll.Add(g);
}

are there any unique identifiers for g, for example a user Id. in which case you could easily use the following:
if (!lll.Any(x=>x.UserId ==g.UserId)) //include system.linq
{
lll.Add(g);
}
You could also look at modifying your stored procedure to not return duplicates.
EDIT ----
Just twigged as to what you actually after, sorry.....
Its just a rough draft but i think this is what you require.
List<GetAllNewsForUser> lll = new List<GetAllNewsForUser>();
foreach (var item in usersLi)
{
NewsInfo nnn = new NewsInfo();
nnn.NewsTitle = item.NewsTitle;
nnn.NewsId = item.NewsId;
if (!lll.Any(x=> x.UserName == item.UserName)
{
GetAllNewsForUser g = new GetAllNewsForUser();
g.UserName = item.UserName;
g.NewsInfos.Add(nnn);
lll.Add(g);
}
else
{
lll.Where(x=>x.UserName == item.Username).FirstOrDefault().NewsInfos.Add(nnn)
}
}

From what I understand so far, you are trying to avoid adding same rows in the list(based on value of some column).
LINQ might help here.
usersLi.GroupBy(e => new {
UserID = e.UserUD
}).Select(g => g.First());

Iterating values

I'm new to linq. I'm using linq to fill some classes from the database.
All my objects are being filled correctly using my linq except for one small thing. Below you can see that for "SAR" "Flight Direction" (rows 15,16) I should have a value for Ascending and a value for Descending. But what I'm getting are two value objects for "Ascending".
Why isn't it looping through my values? What is the LINQ missing?
Here are my DB results:
Here is my LINQ:
using (NpgsqlDataReader reader = command.ExecuteReader())
{
if (reader.HasRows)
{
var groups = reader.Cast<System.Data.Common.DbDataRecord>()
.GroupBy(dr => new { ID = (int)dr["id"], AttID = (int)dr["AttId"] })
.GroupBy(g => g.Key.ID);
typeDataList = (
from typeGroup in groups
let typeRow = typeGroup.First().First()
select new TypeData()
{
ID = (int) typeRow["id"],
Type = (string) typeRow["type"],
Attributes =
(
from attGroup in typeGroup
let attRow = attGroup.First()
select new TypeDataAttribute()
{
ID = (int)attRow["AttId"],
Label = (string)attRow["label"],
PossibleValues =
(
from row in attGroup
where !DBNull.Value.Equals(attRow["AttValueId"])
select new TypeDataAttributeValue() { ID = (int)attRow["AttValueId"], Value = (string)attRow["value"] }
).ToArray()
}
).ToArray()
}
);
}
}

You are taking Value from attRow, you should take it from row.