I have two tables DefaultAttributes and CustomAttributes.
DefaultAttributeTable:
1. Id
2. Product
4. Description
CustomAtrributeTable:
1. Id
2. DefaultAttributeMappingId(FK from DefaultAttributeTable)
3. CustomAtrributeName
4. CustomeAttributeValue
Entries made by user:
user update the values Product -> Vegetables, Description -> House Hold Item, IsOrganic(Custom Attribute created) -> True and IsDisposable(Custom Attribute created) -> True
user update the values Product -> Fruits, Description -> House Hold Item, IsOrganic(Custom Attribute created) -> True and IsDisposable(Custom Attribute created) -> True
user update the values Product -> Plastic, Description -> House Hold Item, IsOrganic(Custom Attribute created) -> False and and IsDisposable(Custom Attribute created) -> False
Then the values will be updated in the table will
DeafaultAtrributeTable:
CustomAttributeTable:
I want to combine the two tables and select the Id, product, IsOrganic, IsDisposable and filter the values based on the isorganic column. Also the custom attribute column name should be taken form the CustomAtrributeTable. Please suggest to me how to achieve it in SQL and Linq Query. The filtered value should be
You may try this in SQL
select DA.Id, DA.Product, CA.CustomeAttributeValue as IsOrganic
from DeafaultAtrributeTable as DA inner join CustomAttributeTable as CA
on DA.Id = CA.DefaultAttributeMappingId
In LINQ
var query =
from DA in DeafaultAtrributeTable
join CA in CustomAttributeTable on DA.ID equals CA.DefaultAttributeMappingId
where CA.CustomeAttributeValue == true
select new { Id = DA.Id, Product = DA.Product, IsOrganic = CA.CustomeAttributeValue };
or LINQ extension method is
var query = DeafaultAtrributeTable // your starting point - table in the "from" statement
.Join(CustomAttributeTable , // the source table of the inner join
DA => DA.ID, // Select the primary key (the first part of the "on" clause in an sql "join" statement)
CA => CA.DefaultAttributeMappingId, // Select the foreign key (the second part of the "on" clause)
(DA, CA) => new { Id = DA.Id, Product = DA.Product, IsOrganic =
CA.CustomeAttributeValue }) // selection
.Where(RES => RES.CA.CustomeAttributeValue == true); // where statement
try this
public class Filtered
{
public int ProductId { get; set; }
public string ProductName { get; set; }
public bool? IsOrganic { get; set; }
public bool? IsDisposable { get; set; }
}
var result = defaultAttributeTable.Join(customAtrributeTable, DAT => DAT.Id, CAT => CAT.DefaultAttributeTableId, (DAT, CAT) =>
new Filtered
{
//your join with null values for opposing isdisposable and isorganic
ProductId = DAT.Id,
IsDisposable = CAT.CustomAtrributeName == "IsDisposable" ? (bool?)CAT.CustomeAttributeValue : null,
IsOrganic = CAT.CustomAtrributeName == "IsOrganic" ? (bool?)CAT.CustomeAttributeValue : null,
ProductName = DAT.Product
}).GroupBy(q => q.ProductId) //group it by productid
.Select(q =>
new Filtered
{
//this will flatten opposing isorganic and isdisposable
ProductId = q.Key,
IsDisposable = q.First(e => e.IsDisposable.HasValue).IsDisposable.Value,
IsOrganic = q.First(e => e.IsOrganic.HasValue).IsOrganic.Value,
ProductName = q.First(e => e.ProductId == q.Key).ProductName
}).ToList();
I have a repository table and add any transaction of products here like this:
productID qty:
103 2
103 -1
in the view of my products I want to show products order by sum of the qty of products > 0
so I write this :
dbContext.tbl_Product.OrderByDescending(n => n.tbl_repository.Sum(x => x.Qty) > 0).ThenByDescending(m => m.ID);
but the performance of this is too slow, is there any other way to make it speedy ?
You can try leveraging the GroupBy method.
First create an (optional) class to hold the results:
public class ProductGroup
{
public string ProductID { get; set; } // or int, whatever your product id's type is
public int QuantitySum { get; set; }
}
I'm not sure how your repository is implemented, but try querying the context directly first and see if you get better results:
using (var db = new ApplicationContext())
{
var products = db.Products
.GroupBy(product => product.ProductID)
.Where(productGroup => productGroup.Sum(p => p.Quantity) > 0)
.Select(productGroup => new ProductGroup { ProductID = productGroup.Key, QuantitySum = productGroup.Sum(product => product.Quantity) })
.OrderByDescending(product => product.ProductID)
.ToList();
// 'products' should be a list of ProductGroup items holding the ID and Sum.
}
ID Name from to
001-1 ABC 2015/05/01 2015/05/31
001-1 ABC 2015/06/01 2015/07/15
003-2 DEF 2015/05/01 2015/05/11
002-1 LMN 2015/05/01 2015/06/15
002-1 LMN 2015/06/16 2015/07/31
003-2 DEF 2015/06/01 2015/07/15
004-5 GHI 2015/05/11 2015/05/15
I want to have merge the records into one which matching the period from 2015/05/15 to 2015/07/15 like the following result in datable.
ID Name from to
001-1 ABC 2015/05/01 2015/07/15
002-1 LMN 2015/05/01 2015/07/31
003-2 and 004-5 are not in new datatable as they are not in the require range.
How can I get this? I only know very basic knowledge about LINQ and it's very fresh to me. thx.
With this class / data as a mockup:
class Item
{
public string ID { get; set; }
public string Name { get; set; }
public DateTime From { get; set; }
public DateTime To { get; set; }
}
List<Item> items = new List<Item> {
new Item { ID = "001-1", Name = "ABC",
From = DateTime.Parse("2015/05/01"),
To = DateTime.Parse("2015/05/31") },
new Item { ID = "001-1", Name = "ABC",
From = DateTime.Parse("2015/06/01"),
To = DateTime.Parse("2015/07/15") },
new Item { ID = "003-2", Name = "DEF",
From = DateTime.Parse("2015/05/01"),
To = DateTime.Parse("2015/05/11") },
new Item { ID = "002-1", Name = "LMN",
From = DateTime.Parse("2015/05/01"),
To = DateTime.Parse("2015/06/15") },
new Item { ID = "002-1", Name = "LMN",
From = DateTime.Parse("2015/06/16"),
To = DateTime.Parse("2015/07/31") },
new Item { ID = "003-2", Name = "DEF",
From = DateTime.Parse("2015/06/01"),
To = DateTime.Parse("2015/07/15") },
new Item { ID = "004-5", Name = "GHI",
From = DateTime.Parse("2015/05/11"),
To = DateTime.Parse("2015/05/15") }
};
you can use the following linq query to get the desired result set:
var result = from i in items
orderby i.From
group i by new { i.ID, i.Name } into iGroup
where iGroup.First().From <= DateTime.Parse("2015/05/15") &&
iGroup.Last().To >= DateTime.Parse("2015/07/1") &&
(iGroup.Last().To - iGroup.First().From).Days + 1 ==
iGroup.Sum(g => (g.To - g.From).Days + 1)
select new Item
{
ID = iGroup.Key.ID,
Name = iGroup.Key.Name,
From = iGroup.First().From,
To = iGroup.Last().To
};
You can adjust datetime comparisons to fit your actual requirement. In the above linq query I am comparing the smallest From date and the largest To date of each group to the matching period dates.
This comparison:
(iGroup.Last().To - iGroup.First().From).Days + 1 ==
iGroup.Sum(g => (g.To - g.From).Days + 1)
checks for groups that have no gaps in their date ranges.
EDIT:
If the source data is stored in a DataTable such as:
DataTable items = new DataTable();
items.Columns.Add("ID", typeof(string));
items.Columns.Add("Name", typeof(string));
items.Columns.Add("From", typeof(DateTime));
items.Columns.Add("To", typeof(DateTime));
then the linq query becomes a bit more complicated:
var q = from i in items.AsEnumerable()
orderby i.Field<DateTime>("From")
group i by new { ID = i.Field<string>("ID"), Name = i.Field<string>("Name") } into iGroup
where iGroup.First().Field<DateTime>("From") <= DateTime.Parse("2015/05/15") &&
iGroup.Last().Field<DateTime>("To") >= DateTime.Parse("2015/07/1") &&
(iGroup.Last().Field<DateTime>("To") - iGroup.First().Field<DateTime>("From")).Days + 1 ==
iGroup.Sum(g => (g.Field<DateTime>("To") - g.Field<DateTime>("From")).Days + 1)
select new
{
ID = iGroup.Key.ID,
Name = iGroup.Key.Name,
From = iGroup.First().Field<DateTime>("From"),
To = iGroup.Last().Field<DateTime>("To")
};
The above query returns an IEnumerable of anonymous type. It can be converted back to a DataTable using Reflection (see this post for example).
I have a database table. What I want is to get data using group by clause as I have used in below code.
Note that Decision is another table. now I want that all the decisions related to a specific Meeting Title should be shown in list.like
meetingtitle1=decision1,decison2,decison3
meetingtitle2=decision1,decison2
but below code returns only one decisiontitle.
public List<NewMeetings> GetAllMeetings()
{
var xyz = (from m in DB.MeetingAgenda
//join mp in Meeting on m.MeetingId equals mp.MeetingId
//where m.MeetingId == 2
group m by new { m.Meeting.MeetingTitle } into grp
select new NewMeetings
{
// meetingid = grp.Key.MeetingId,
meetingtitle = grp.Key.MeetingTitle,
decision = grp.Select(x => x.Decision.DecisionTitle).FirstOrDefault(),
total = grp.Count()
}).ToList();
List<NewMeetings> list = xyz.ToList();
return list;
}
public class NewMeetings
{
public int meetingid;
public string meetingtitle;
public string decision;
public int total;
}
Can somebody please tell me how to return a list of decisions to a specific Meetingtitle?
You are doing a FirstOrDefault on the list of decisions which obviously means you are only getting a single value. Instead you can join them all together into one longer string (separated by commas as you indicated in the question) by changing this line:
decision = grp.Select(x => x.Decision.DecisionTitle).FirstOrDefault(),
To this:
decision = string.Join(",", grp.Select(x => x.Decision.DecisionTitle)),
However, as the string.Join is not recognised by Linq to Entities, you need to do the string.Join after the data has been retrieved (i.e. after the ToList):
var xyz = (from m in DB.MeetingAgenda
group m by new { m.Meeting.MeetingTitle } into grp
select new
{
meetingtitle = grp.Key.MeetingTitle,
decisions = grp.Select(x => x.Decision.DecisionTitle),
total = grp.Count()
})
.ToList()
.Select(m => new NewMeetings
{
meetingtitle = m.meetingtitle,
decision = string.Join(",", m.decisions),
total = m.total
});
I'm trying to work with grouped data coming back from SQL.
The method I'm writing is to provide the data for a "Case Status Overview" screen.
It must produce a nested XML document.
Now, I could do it the easy way, but I'm trying to learn whether it's possible to use the linq "group by" statement and then to project the data already nested. (the easy way would be just to pull back the data in a tabular fashion from the database and then for-loop through it forming the Xml document for output)
Here is the data hierarchy:
Every Case has a DebtType and every DebtType has a Client.
Here is the SQL that retrieves the data:
SELECT ClientNames.ClientID ,
ClientNames.ClientCode ,
ClientNames.ClientName ,
DebtTypes.DebtTypeID ,
DebtTypes.DebtTypeShortDesc ,
DebtTypes.DebtTypeLongDesc ,
Cases.CurrentStateCode ,
SUM(1 - CAST(Cases.CaseClosed AS INT)) AS OpenCaseCount ,
SUM(CAST(Cases.CaseClosed AS INT)) AS ClosedCaseCount ,
SUM(CAST(Cases.CaseOnHold AS INT)) AS OnHoldCaseCount ,
SUM(CAST(Cases.CaseReferred AS INT)) AS ReferredCaseCount ,
COUNT(Cases.CaseID) AS TotalCaseCount ,
SUM(Cases.CaseTotalPaid) AS TotalAmountPaid ,
SUM(Cases.CaseCurrentOutstandingAmount) AS TotalAmountOutstanding,
SUM(Cases.CaseTotalDebtWrittenOff) AS TotalAmountWrittenOff ,
SUM(Cases.CaseTotalDebtCancelled) AS TotalAmountCancelled
FROM ClientNames
INNER JOIN ClientDebtTypes
ON ClientNames.ClientID = ClientDebtTypes.ClientID
INNER JOIN DebtTypes
ON ClientDebtTypes.DebtTypeID = DebtTypes.DebtTypeID
INNER JOIN Cases
ON ClientDebtTypes.ClientDebtTypeID = Cases.CaseClientDebtTypeID
GROUP BY ClientNames.ClientID ,
ClientNames.ClientCode ,
ClientNames.ClientName ,
DebtTypes.DebtTypeID ,
DebtTypes.DebtTypeShortDesc,
DebtTypes.DebtTypeLongDesc ,
Cases.CurrentStateCode
ORDER BY ClientNames.ClientID,
DebtTypes.DebtTypeID,
CurrentStateCode
Using Linqer it converts it to:
from clientnames in db.ClientNames
join clientdebttypes in db.ClientDebtTypes on clientnames.ClientID equals clientdebttypes.ClientID
join debttypes in db.DebtTypes on clientdebttypes.DebtTypeID equals debttypes.DebtTypeID
join cases in db.Cases on new { ClientDebtTypeID = clientdebttypes.ClientDebtTypeID } equals new { ClientDebtTypeID = cases.CaseClientDebtTypeID }
group new {clientnames, debttypes, cases} by new {
clientnames.ClientID,
clientnames.ClientCode,
clientnames.ClientName1,
debttypes.DebtTypeID,
debttypes.DebtTypeShortDesc,
debttypes.DebtTypeLongDesc,
cases.CurrentStateCode
} into g
orderby
g.Key.ClientID,
g.Key.DebtTypeID,
g.Key.CurrentStateCode
select new {
ClientID = (System.Int32?)g.Key.ClientID,
g.Key.ClientCode,
g.Key.ClientName1,
DebtTypeID = (System.Int32?)g.Key.DebtTypeID,
g.Key.DebtTypeShortDesc,
g.Key.DebtTypeLongDesc,
g.Key.CurrentStateCode,
OpenCaseCount = (System.Int64?)g.Sum(p => 1 - Convert.ToInt32(p.cases.CaseClosed)),
ClosedCaseCount = (Int32?)g.Sum(p => Convert.ToInt32(p.cases.CaseClosed)),
OnHoldCaseCount = (Int32?)g.Sum(p => Convert.ToInt32(p.cases.CaseOnHold)),
ReferredCaseCount = (Int32?)g.Sum(p => Convert.ToInt32(p.cases.CaseReferred)),
TotalCaseCount = (Int64?)g.Count(p => p.cases.CaseID != null),
TotalAmountPaid = (System.Decimal?)g.Sum(p => p.cases.CaseTotalPaid),
TotalAmountOutstanding = (System.Decimal?)g.Sum(p => p.cases.CaseCurrentOutstandingAmount),
TotalAmountWrittenOff = (System.Decimal?)g.Sum(p => p.cases.CaseTotalDebtWrittenOff),
TotalAmountCancelled = (System.Decimal?)g.Sum(p => p.cases.CaseTotalDebtCancelled)
}
Now as I mentioned, I could stop there and right a for loop to create the Xml data.
But I'm trying to create a nested group (IGrouping<ClientName,IGrouping<DebtType,SummaryClass>>)
and then project the data in a nested format.
Now we're using LinqToXsd to create strong type wrappers for out Xml documents, but essentially all this means is that out output type is:
private class ClientSummary
{
public string ClientName { get; set; }
public IList<DebtTypeSummary> DebtTypes { get; set; }
}
private class DebtTypeSummary
{
public string DebtType { get; set; }
public IList<StateCodeSummary> StateCodes { get; set; }
}
private class StateCodeSummary
{
public string StateCode { get; set; }
public int TotalCount { get; set; }
public decimal TotalAmountPaid { get; set; }
//etc
//etc
//etc
}
Now I got as far as writing the following Linq:
var grouping = from cases in db.Cases
join clientdebttypes in db.ClientDebtTypes on cases.CaseClientDebtTypeID equals clientdebttypes.ClientID
join debttypes in db.DebtTypes on clientdebttypes.DebtTypeID equals debttypes.DebtTypeID
group cases by new ClientDebtTypePair() { ClientDebtType = clientdebttypes, DebtType = debttypes } into casesByClientDebtTypes
join clientnames in db.ClientNames on casesByClientDebtTypes.Key.ClientDebtType.ClientName equals clientnames
group casesByClientDebtTypes by clientnames;
var projected = from casesByClientDebtTypes in grouping
let client = casesByClientDebtTypes.Key
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = new Client()
{
ClientID = client.ClientID,
DisplayName = client.ClientName1,
},
DebtTypes = from cases in casesByClientDebtTypes
let debttype = cases.Key.DebtType
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType.DebtTypesLocalType()
{
DebtType = new DebtType()
{
DebtTypeID = debttype.DebtTypeID,
Description = debttype.DebtTypeLongDesc,
DisplayName = debttype.DebtTypeShortDesc,
},
StatesCodes = from cases2 in cases
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType.DebtTypesLocalType.StatesCodesLocalType()
{
ClosedCasesCount = cases2.Sum(p => Convert.ToInt32(p.cases.CaseClosed))
which joins and groups the database tables and then tries to project the result a ClientSummary (the class names are different but that's because the above is a simplified view of the output classes). I fail completely when I've drilled all the way down to the Cases table and I find that I don't really understand how to do agregate functions. They appear to only be available on IGrouping<K, T>s and it seems I've just got confused.
I need to also ensure that the summaries are calculated server side, pulling back millions of cases would be bad.
Can anybody help me with this one? Is this even possible?
Regards,
James.
-------### UPDATE 1 ###-------
OK, been working on this again today.
I decided to use Linq2SQL to pull pack 2D data and then reformat it using Linq2Objects.
Here is what I started with:
var sql = from clientnames in db.ClientNames
join clientdebttypes in db.ClientDebtTypes on clientnames.ClientID equals clientdebttypes.ClientID
join debttypes in db.DebtTypes on clientdebttypes.DebtTypeID equals debttypes.DebtTypeID
join cases in db.Cases on new { ClientDebtTypeID = clientdebttypes.ClientDebtTypeID } equals new { ClientDebtTypeID = cases.CaseClientDebtTypeID }
group new { clientnames, debttypes, cases } by new
{
clientnames.ClientID,
clientnames.ClientCode,
clientnames.ClientName1,
debttypes.DebtTypeID,
debttypes.DebtTypeShortDesc,
debttypes.DebtTypeLongDesc,
cases.CurrentStateCode
} into g
orderby
g.Key.ClientID,
g.Key.DebtTypeID,
g.Key.CurrentStateCode
select new
{
Client = new Client{ ClientID = g.Key.ClientID, DisplayName = g.Key.ClientName1 },
DebtType = new DebtType{ DebtTypeID = g.Key.DebtTypeID, DisplayName = g.Key.DebtTypeShortDesc, Description = g.Key.DebtTypeLongDesc },
StateSummary = new LoadCaseStatusOverviewScreenOutput.ClientsLocalType.DebtTypesLocalType.StatesCodesLocalType()
{
StateCode = g.Key.CurrentStateCode,
OpenCasesCount = g.Sum(p => 1 - Convert.ToInt32(p.cases.CaseClosed)),
ClosedCasesCount = g.Sum(p => Convert.ToInt32(p.cases.CaseClosed)),
OnHoldCasesCount = g.Sum(p => Convert.ToInt32(p.cases.CaseOnHold)),
ReferredCasesCount = g.Sum(p => Convert.ToInt32(p.cases.CaseReferred)),
TotalCasesCount = g.Count(p => p.cases.CaseID != null),
TotalAmountPaid = g.Sum(p => p.cases.CaseTotalPaid),
TotalAmountOutstanding = g.Sum(p => p.cases.CaseCurrentOutstandingAmount),
TotalAmountWrittenOff = g.Sum(p => p.cases.CaseTotalDebtWrittenOff),
TotalAmountCancelled = g.Sum(p => p.cases.CaseTotalDebtCancelled),
}
};
var res = sql.ToList();
output.Clients = (from results in res
group results by results.Client into resultsByClient
from resultsByDebtType in
(from results in resultsByClient
group results by results.DebtType)
group resultsByDebtType by resultsByClient.Key into resultsByDebtTypeByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = resultsByDebtTypeByClient.Key,
DebtTypes = (from resultsByDebtType in resultsByDebtTypeByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType.DebtTypesLocalType()
{
DebtType = resultsByDebtType.Key,
StatesCodes = (from results in resultsByDebtType
let summary = results.StateSummary
select results.StateSummary).ToList()
}).ToList()
}).ToList();
That runs, but produces one Client/DebtType/Summary set for every result. So even though there is only one client in this case, I end up with 1300 clients, all identical.
I simplified it to the following:
output.Clients = (from results in res
group results by results.Client into resultsByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = resultsByClient.Key,
DebtTypes = null,
}).ToList();
That produces 1300 clients. Next I tried this:
output.Clients = (from results in res
group results by results.Client.ClientID into resultsByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = new Client { ClientID = resultsByClient.Key },
DebtTypes = null,
}).ToList();
And THAT produces ONE client (hurray!). Except I loose all the client information (boo!)
Guessing that as it's comparing client by refernce instead of by content I wrote the following:
public partial class Client
{
public static bool operator ==(Client left, Client right)
{
return left.ClientID == right.ClientID;
}
public static bool operator !=(Client left, Client right)
{
return left.ClientID != right.ClientID;
}
public override int GetHashCode()
{
return ClientID;
}
}
That did nothing. It repeatedly calls GetHashCode(), which I fudged to force it to return the same hash code for any matching ClientID, but it still created 1300 Client groups.
Regards,
James.
-------### UPDATE 2 ###-------
OK, I thought I would have a go at making the Linq2Sql output only simple values for grouping by:
g.Key.ClientID,
g.Key.ClientName1,
g.Key.DebtTypeID,
g.Key.DebtTypeShortDesc,
g.Key.DebtTypeLongDesc,
And then changed the test Linq2Objects to:
output.Clients = (from results in res
group results by new { ClientID = results.ClientID, DisplayName = results.ClientName1 } into resultsByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = new Client { ClientID = resultsByClient.Key.ClientID, DisplayName = resultsByClient.Key.DisplayName },
DebtTypes = null,
}).ToList();
That works. So anonymous types compare in the way I want them to, by content not reference (apparently)
This does not:
output.Clients = (from results in res
group results by new SiDemClient { ClientID = results.ClientID, DisplayName = results.ClientName1 } into resultsByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = resultsByClient.Key,//new Client { ClientID = resultsByClient.Key.ClientID, DisplayName = resultsByClient.Key.DisplayName },
DebtTypes = null,
}).ToList();
That still creates 1300 groups.
So, anonymous types compare in a magical way that I don't understand. How can I make my Client class compare like an anonymous type?
Regards,
James.
-------### SOLUTION FOUND ###-------
-------### MANY THANKS TO Enigmativity ###-------
I needed to override the Equals() method instead of implementing the == operator.
Now the grouping works and I have a wonderful Xml document to reutrn!
public partial class SiDemClient
{
public override bool Equals(object obj)
{
if (obj is SiDemClient)
{
return this.ClientID.Equals(((SiDemClient)obj).ClientID);
}
return false;
}
public override int GetHashCode()
{
return ClientID;
}
}
Many Thanks,
James.
When you override GetHashCode you must also override Equals. The == & != operators are irrelevant.
Try with this:
public partial class Client
{
public override bool Equals(object obj)
{
if (obj is Client)
{
return this.ClientID.Equals(((Client)obj).ClientID);
}
return false;
}
public override int GetHashCode()
{
return this.ClientID.GetHashCode();
}
}
See if that helps.