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I have list say list of customers and inside each list there is another list of orders
Class Customer
{
int ID,
string Name
List<Order> orders
}
Class Order{
int ID,
string Name
}
Also have a integer list of filteredorderIds = {1,2,3,4}
I want to filter the list of customers who has got orderIds from filteredorderIds list.
So far I am stuck at query like
var filteredCustomers = Customers.Where(x => x.Orders.Any(filteredorderIds.contains(y => y.Id)));
please give credit to #Johnathan Barclay, since he posted faster than i typed example
void Main()
{
var customers = new List<Customer>(){
new Customer(){
ID =1,
Name = "Cust1",
orders = new List<Order>(){
new Order(){ID = 4, Name = "o11"},
new Order(){ID = 5, Name = "o12"},
new Order(){ID = 6, Name = "o13"}
}
},
new Customer(){
ID = 2,
Name = "Cust2",
orders = new List<Order>(){
new Order(){ID = 3, Name = "o21"},
new Order(){ID = 7, Name = "o22"},
new Order(){ID = 8, Name = "o23"}
}
}
};
customers.Where(w =>
w.orders.Any(w => filteredorderIds.Contains(w.ID))
).Dump();
}
List<int> filteredorderIds = new List<int>() { 1, 2, 3, 4 };
public class Customer
{
public int ID { get; set; }
public string Name { get; set; }
public List<Order> orders { get; set; }
}
public class Order
{
public int ID { get; set; }
public string Name { get; set; }
}
I have a list of my issue class
var firstList = new List<object> {
new { id =1, Name = "item-1"},
new { id =2, Name = "item-2"},
new { id =3, Name = "item-3"},
new { id =4, Name = "item-4"}
}
And my second list is like this
var secondList = new List<Issue> {
new Issue{ id =1, Date = "01.01.2017"},
new Issue{ id =2, Date = "01.02.2017"}
}
So I want to create a new list like this. (same id objects will be isPlanned=true)
var firstList = new List<object> {
new { id =1, Name = "item-1", isPlanned=true, Date = "01.01.2017"},
new { id =2, Name = "item-2", isPlanned=true, Date = "01.02.2017"},
new { id =3, Name = "item-3", isPlanned=false },
new { id =4, Name = "item-4", isPlanned=false }
}
How can I do this linq functions or lambda operations?
You can use left join for this:
var items = new[] {
new { id =1, Name = "item-1"},
new { id =2, Name = "item-2"},
new { id =3, Name = "item-3"},
new { id =4, Name = "item-4"}
};
var issues = new[] {
new { id =1, Date = "01.01.2017"},
new { id =2, Date = "01.02.2017"}
};
var joined = from item in items
join issue in issues on item.id equals issue.id into gj
from sub in gj.DefaultIfEmpty()
select new { item.id, item.Name, isPlanned=sub?.Date != null, sub?.Date };
foreach (var t in joined) {
Console.WriteLine("{0} {1} {2} {3}", t.id, t.Name, t.isPlanned, t.Date);
}
The result will have nulls when dates are missing, i.e.
new { id =1, Name = "item-1", isPlanned=true, Date = "01.01.2017"},
new { id =2, Name = "item-2", isPlanned=true, Date = "01.02.2017"},
new { id =3, Name = "item-3", isPlanned=false, Date = null },
new { id =4, Name = "item-4", isPlanned=false, Date = null }
Demo.
If you wanted to use a lambda expression, you could do it the following way:
List<Foo> foos = new List<Foo>()
{
new Foo(){ Id = 1, Name = "item-1"},
new Foo(){ Id = 2, Name = "item-2"},
new Foo(){ Id = 3, Name = "item-3"},
new Foo(){ Id = 4, Name = "item-4"}
};
List<Bar> bars = new List<Bar>()
{
new Bar(){ Id = 1, Date = "01.01.2017"},
new Bar(){ Id = 2, Date = "01.02.2017"}
};
IEnumerable<dynamic> result = foos.GroupJoin(bars,
f => f.Id,
b => b.Id,
(foo, bar) => new
{
Id = foo.Id,
Name = foo.Name,
isPlanned = String.IsNullOrEmpty(bar.SingleOrDefault()?.Date),
Date = bar.SingleOrDefault()?.Date
});
here are the classes
public class Foo
{
public int Id { get; set; }
public string Name { get; set; }
}
public class Bar
{
public int Id { get; set; }
public string Date { get; set; }
}
I noticed also from the comments from another answer that you are not able to use C#6.0, so this section would not work for you
isPlanned = String.IsNullOrEmpty(bar.SingleOrDefault()?.Date),
Date = bar.SingleOrDefault()?.Date
You can replace that with the following:
isPlanned = bar.SingleOrDefault() == null ? false : String.IsNullOrEmpty(bar.SingleOrDefault().Date),
Date = bar.SingleOrDefault() == null ? null : bar.SingleOrDefault().Date
I have a question about a LINQ grouping.
I thought that grouping would be a simple matter of using the GroupBy function on the result set and specifying what to group it by. However my items appear to not be grouping together and instead are displaying as if the GroupBy function wasn't there. I want to group by the itemPk, but I'm can't seem to do it. I have tried grouping by both category.ItemFk and Item.Itempk, but no luck. Could someone give me a pointer on this?
var itemIds = items.Select(i => i.ItemId).ToList();
var itemAndCatJoin =
from item in Context.SCS_Items
join category in Context.SCS_ItemCategories
on item.ItemPk equals category.ItemFk
into temp
from category in temp.DefaultIfEmpty()
select new ExportItemTable
{
Category = category,
Item = item
};
return itemAndCatJoin.Where(i => itemIds.Contains(i.Item.ItemPk))
.GroupBy(n => new {n.Item, n.Category})
.Select(i => new ExportableItem
{
ItemPk = i.Key.Item.ItemPk,
Name = i.Key.Item.Name,
Description = i.Key.Item.Description,
Price = i.Key.Item.Price,
Category = i.Key.Category.Category.Category_Name,
GLDepartment = i.Key.Category.GL_Department.Name ?? "",
GLName = i.Key.Category.GL_Name.Name ?? "",
StartDate = i.Key.Item.StartDate,
EndDate = i.Key.Item.EndDate,
FiscalYear = i.Key.Item.SCS_FiscalYear.Name,
School = i.Key.Item.School != null ? i.Key.Item.School.School_Name : i.Key.Item.Board.Board_Name,
Beneficiary = i.Key.Item.SCS_Beneficiary.Name,
Quantity = i.Key.Item.MaxQuantity,
Deleted = i.Key.Item.DeletedFlag,
OptionalStudents = i.Key.Item.SCS_Attachments.Where(a => !a.IsRequired).SelectMany(a => a.SCS_StudentAttachments).Where(s => !s.DeletedFlag).Select(s => s.StudentFk).Distinct().Count(),
RequiredStudents = i.Key.Item.SCS_Attachments.Where(a => a.IsRequired).SelectMany(a => a.SCS_StudentAttachments).Where(s => !s.DeletedFlag).Select(s => s.StudentFk).Distinct().Count(),
IsPublic = i.Key.Item.IsPublic,
AllowRecurring = i.Key.Item.AllowRecurringPayments,
EffectiveCutoff = i.Key.Item.SCS_Attachments.Where(a => !a.DeletedFlag && a.CourseDropCutoff.HasValue).Select(a => a.CourseDropCutoff).OrderBy(a => a).FirstOrDefault(),
CreatedDate = i.Key.Item.CreatedDate
}).OrderBy(i => i.ItemPk).ToList();
}
your groupbyy is indeed doing nothing for you, you need to tell the groupby what to group by....
like
.GroupBy(n => n.Category)
Here is a simple example to your grouping question:
class Program
{
static void Main()
{
var allItems = GetAllItems();
var groups = from item in allItems
group item by item.Category
into newGroup
select newGroup;
foreach (var group in groups)
{
Console.WriteLine($"\nCategory: {group.Key}");
foreach (var item in group)
{
Console.WriteLine($"{item.Name}: {item.Price}");
}
}
Console.ReadLine();
}
static List<Category> GetAllCategories()
{
return new List<Category>()
{
new Category() { Id = 1, Name = "Programming Books" },
new Category() { Id = 2, Name = "Fiction Books" }
};
}
static List<Item> GetAllItems()
{
return new List<Item>()
{
new Item() { Id = 1, Name = "Embedded Linux", Category = 1, Price = 9.9 },
new Item() { Id = 2, Name = "LINQ In Action", Category = 1, Price = 36.19 },
new Item() { Id = 3, Name = "C# 6.0 and the .NET 4.6 Framework", Category = 1, Price = 40.99 },
new Item() { Id = 4, Name = "Thinking in LINQ", Category = 1, Price = 36.99 },
new Item() { Id = 5, Name = "The Book Thief", Category = 2, Price = 7.99 },
new Item() { Id = 6, Name = "All the Light We Cannot See", Category = 2, Price = 16.99 },
new Item() { Id = 7, Name = "The Life We Bury", Category = 2, Price = 8.96 }
};
}
}
public class Item
{
public int Id { get; set; }
public string Name { get; set; }
public double Price { get; set; }
public int Category { get; set; }
}
public class Category
{
public int Id { get; set; }
public string Name { get; set; }
}
This example is simple enough for anyone new to LINQ. I am sure you can make some adjustment to make it work for your specific issue. Hope this will help.
My GroupBy is performing well. I'm getting the Output
I need to Sort the Group Names
The Brown Color Block, represents the Group.
The Red Color Box within the Brown Color Block, represents the Manager
Peter Block (Brown Box) Should Come first
Raj Block (Brown Box) Should Come Second
Sunny Block (Brown Box) Should Come Third
Each Block Should Group By Boss(Manager) and Assistant (Boss don't have the
SID). After GroupBy the Name should be in Sorted Order, within the Group
the Assistant Names are also in the Sorted Order.
The Model Classes:
public class Person
{
public int ID { get; set; }
public int SID { get; set; }
public string Name { get; set; }
public string Department { get; set; }
public string Gender { get; set; }
public string Role { get; set; }
}
public class Boss
{
public int ID { get; set; }
public int SID { get; set; }
public string Name { get; set; }
public string Department { get; set; }
public string Gender { get; set; }
public string Role { get; set; }
public List<Person> Employees { get; set; }
}
The Main Functionality Source Code:
void Main()
{
List<Boss> BossList = new List<Boss>()
{
new Boss()
{
ID = 101,
Name = "Sunny",
Department = "Development",
Gender = "Male",
Role = "Manager",
Employees = new List<Person>()
{
new Person() {ID = 101, SID = 102, Name = "Peter", Department = "Development", Gender = "Male", Role = "Assistant"},
new Person() {ID = 101, SID = 103, Name = "Emma Watson", Department = "Development", Gender = "Female", Role = "Assistant"},
}
},
new Boss()
{
ID = 104,
Name = "Raj",
Department = "Development",
Gender = "Male",
Role = "Manager",
Employees = new List<Person>()
{
new Person() {ID = 104, SID = 105, Name = "Kaliya", Department = "Development", Gender = "Male", Role = "Assistant"},
new Person() {ID = 104, SID = 103, Name = "Emma Watson", Department = "Development", Gender = "Female", Role = "Assistant"},
},
},
new Boss()
{
ID = 102,
Name = "Peter",
Department = "Development",
Gender = "Male",
Role = "Manager",
Employees = new List<Person>()
{
new Person() {ID = 102, SID = 105, Name = "Kaliya", Department = "Development", Gender = "Male", Role = "Assistant"},
new Person() {ID = 102, SID = 103, Name = "Emma Watson", Department = "Development", Gender = "Female", Role = "Assistant"},
}
}
};
List<Person> EmpList = BossList.SelectMany(i =>
new[] {
new Person()
{
ID = i.ID,
SID = i.SID,
Name = i.Name,
Gender = i.Gender,
Department = i.Department,
Role = i.Role
}
}.Concat(i.Employees)
).ToList().GroupBy(s => s.ID).SelectMany(h => h.GroupBy(g => g.SID).SelectMany(u => u.OrderBy(k=> k.Name))).ToList();
}
You can do by adding the ThenBy extension method after the Order by to apply the secondary sort. In fact, the ThenBy can be called multiple times for sorting on multiple property. I have modified the last line of your code to show how you can achieve this.
).ToList().GroupBy(s => s.ID).SelectMany(h => h.GroupBy(g => g.SID).SelectMany(u => u.OrderBy(k=> k.Name).ThenBy(l => l.<<secondproperty>>))).ToList();
The datastructure already establishes the groups. There is no need to re-group.
List<Person> result = (
from boss in BossList
order by boss.Name
let orderedEmployees = boss.Employees.OrderBy(emp => emp.Name)
let bossPerson = new Person(boss)
let people = new List<Person>() { bossPerson }.Concat(orderedEmployees)
from person in people
select person).ToList();
If you prefer the lambda syntax:
List<Person> result = BossList
.OrderBy(boss => boss.Name)
.SelectMany(boss => {
IEnumerable<Person> orderedEmployees = boss.Employees.OrderBy(emp => emp.Name);
Person bossPerson = new Person(boss);
return new List<Person>() { bossPerson }.Concat(orderedEmployees);
})
.ToList();
I have some flat data coming from the database that looks like this:
List<FlatDataGroup> elements = new List<FlatDataGroup>()
{
new FlatDataGroup {Text = "", GroupID = 1, ParentGroupID = 0, GroupName = "Admin", UserID = 1, UserName = "John Doe"},
new FlatDataGroup {Text = "", GroupID = 1, ParentGroupID = 0, GroupName = "Admin", UserID = 2, UserName = "Jane Smith"},
new FlatDataGroup {Text = "", GroupID = 2, ParentGroupID = 1, GroupName = "Support", UserID = 3, UserName = "Johnny Support"},
new FlatDataGroup {Text = "", GroupID = 3, ParentGroupID = 2, GroupName = "SubSupport", UserID = 4, UserName = "Sub Johnny Support"},
new FlatDataGroup {Text = "", GroupID = 4, ParentGroupID = 1, GroupName = "Production", UserID = 5, UserName = "Johnny Production"}
};
I would like to convert it to this:
List<Group> model = new List<Group>
{
new Group()
{
ID = 1,
Name = "Admin",
ParentGroupID = 0,
Type = "Group",
Users = new List<User>()
{
new User()
{
ID = 1,
Name = "John Doe",
GroupID = 1,
Type = "User",
},
new User()
{
ID = 2,
Name = "Jane Smith",
GroupID = 1,
Type = "User",
},
},
Groups = new List<Group>
{
new Group()
{
ID = 2,
Name = "Support",
ParentGroupID = 1,
Type = "Group",
Users = new List<User>()
{
new User()
{
ID = 3,
Name = "Johnny Support",
GroupID = 2,
Type = "User",
}
},
Groups = new List<Group>()
{
new Group()
{
ID = 3,
Name = "SubSupport",
ParentGroupID = 2,
Type = "Group",
Users = new List<User>()
{
new User()
{
ID = 4,
Name = "Sub Johnny Support",
GroupID = 3,
Type = "User",
}
},
Groups = null
}
}
},
new Group()
{
ID = 4,
Name = "Production",
ParentGroupID = 1,
Type = "Group",
Users = new List<User>()
{
new User()
{
ID = 5,
Name = "Johnny Production",
GroupID = 4,
Type = "User",
}
},
Groups = null
}
}
}
};
which will ultimately display like this in a treeview:
+Admin (Group)
John Doe (User)
Jane Smith (User)
+Support (Group)
Johnny Support (User)
+SubSupport (Group)
Sub Johnny Support (User)
+Production (Group)
Johnny Production (User)
This is what I've come up with so far to transform the flat data into the model above:
List<Group> model = new List<Group>();
var parentGrouping = elements.GroupBy(x => x.ParentGroupID);
foreach (var parentGroup in parentGrouping)
{
var grouping = parentGroup.GroupBy(y => y.GroupID);
foreach (var group in grouping)
{
Group groupItem = new Group()
{
ID = group.FirstOrDefault().GroupID,
Name = group.FirstOrDefault().GroupName,
ParentGroupID = group.FirstOrDefault().ParentGroupID,
Type = "Group",
Users = new List<User>()
};
foreach (var user in group)
{
groupItem.Users.Add(new User()
{
ID = user.UserID,
Name = user.UserName,
GroupID = user.GroupID,
Type = "User",
});
}
model.Add(groupItem);
}
}
All my groups come out along with their children users but the hierarchy is not preserved. I think I may need to do this recursively but I can't seem to get my head around it. Any help would be greatly appreciated.
Here are the models for the sake of completeness:
public class FlatDataGroup
{
public string Text { get; set; }
public int GroupID { get; set; }
public int ParentGroupID { get; set; }
public string GroupName { get; set; }
public int UserID { get; set; }
public string UserName { get; set; }
}
public class Group
{
public int ID { get; set; }
public int ParentGroupID { get; set; }
public string Name { get; set; }
public List<Group> Groups { get; set; }
public List<User> Users { get; set; }
public string Type { get; set; }
}
public class User
{
public int ID { get; set; }
public int GroupID { get; set; }
public string Name { get; set; }
public string Type { get; set; }
}
I'd do this in 3 passes:
Create all Group classes and populate them with data other than child groups, adding them incrementally to a dictionary mapping ID to Group.
Loop through all the groups in the dictionary and add children to their parents' Groups list of children.
Return a filtered list of all groups with no parent group -- these are the root groups. (I also sorted them by ID to remove the random ordering that the dictionary will introduce.)
Thus:
public static class FlatDataGroupExtensions
{
public const string UserType = "User";
public const string GroupType = "Group";
public static List<Group> ToGroups(this IEnumerable<FlatDataGroup> elements)
{
// Allocate all groups and index by ID.
var groups = new Dictionary<int, Group>();
foreach (var element in elements)
{
Group group;
if (!groups.TryGetValue(element.GroupID, out group))
groups[element.GroupID] = (group = new Group() { ID = element.GroupID, Name = element.GroupName, ParentGroupID = element.ParentGroupID, Type = GroupType });
group.Users.Add(new User() { GroupID = element.GroupID, ID = element.UserID, Name = element.UserName, Type = UserType });
}
// Attach child groups to their parents.
foreach (var group in groups.Values)
{
Group parent;
if (groups.TryGetValue(group.ParentGroupID, out parent) && parent != group) // Second check for safety.
parent.Groups.Add(group);
}
// Return only root groups, sorted by ID.
return groups.Values.Where(g => !groups.ContainsKey(g.ParentGroupID)).OrderBy(g => g.ID).ToList();
}
}
I also modified your Group class a little to automatically allocate the lists:
public class Group
{
List<Group> groups = new List<Group>();
List<User> users = new List<User>();
public int ID { get; set; }
public int ParentGroupID { get; set; }
public string Name { get; set; }
public string Type { get; set; }
public List<Group> Groups { get { return groups; } }
public List<User> Users { get { return users; } }
public override string ToString()
{
return string.Format("Group: ID={0}, Name={1}, Parent ID={2}, #Users={3}, #Groups={4}", ID, Name, ParentGroupID, Users.Count, Groups.Count);
}
}