c# - "Affaire" dans l'instruction order by - Stack Overflow

Hello I have the following linq statement:

IEnumerable<TabTransaktion> allTransactions 
    = TabTransaktions1.Union(TabTransaktions2)
                      .Where(trans => trans.TabVorgang != null).
                       .OrderBy(tran => tran.TabVorgang.Wirkdatum)
                      .OrderByDescending(trans2 => trans2.TabVorgang.ID);

But I want the second order by descending when only trans2.TabVorgang.ID equals to 0. So I need a "case" in "order by clause" for LinQ. A LinQ equivalent of something like this:

SELECT BusinessEntityID, SalariedFlag
FROM HumanResources.Employee
ORDER BY CASE SalariedFlag WHEN 1 THEN BusinessEntityID END DESC
        ,CASE WHEN SalariedFlag = 0 THEN BusinessEntityID END;
GO

I would appreciate any help.

Assuming SalariedFlag is a bool (in SQL of type bit), the two ordering expressions are exclusively mutual. In other words, the main query can be separated into two disjunctive queries and the final result is the union of them:

IEnumerable<TabTransaktion> mainQuery
    = TabTransaktions1.Union(TabTransaktions2)
                      .Where(trans => trans.TabVorgang != null);

var queryOne  =  mainQuery.Where(p=>p.SalariedFlag ==1)
                       .OrderByDescending(tran => tran.BusinessEntityID );

var queryTwo  =  mainQuery.Where(p=>p.SalariedFlag ==0)
                       .OrderBy(tran => tran.BusinessEntityID);

var finalResult = queryOne.Union(queryTwo);

Hello I have the following linq statement:

IEnumerable<TabTransaktion> allTransactions 
    = TabTransaktions1.Union(TabTransaktions2)
                      .Where(trans => trans.TabVorgang != null).
                       .OrderBy(tran => tran.TabVorgang.Wirkdatum)
                      .OrderByDescending(trans2 => trans2.TabVorgang.ID);

But I want the second order by descending when only trans2.TabVorgang.ID equals to 0. So I need a "case" in "order by clause" for LinQ. A LinQ equivalent of something like this:

SELECT BusinessEntityID, SalariedFlag
FROM HumanResources.Employee
ORDER BY CASE SalariedFlag WHEN 1 THEN BusinessEntityID END DESC
        ,CASE WHEN SalariedFlag = 0 THEN BusinessEntityID END;
GO

I would appreciate any help.

Assuming SalariedFlag is a bool (in SQL of type bit), the two ordering expressions are exclusively mutual. In other words, the main query can be separated into two disjunctive queries and the final result is the union of them:

IEnumerable<TabTransaktion> mainQuery
    = TabTransaktions1.Union(TabTransaktions2)
                      .Where(trans => trans.TabVorgang != null);

var queryOne  =  mainQuery.Where(p=>p.SalariedFlag ==1)
                       .OrderByDescending(tran => tran.BusinessEntityID );

var queryTwo  =  mainQuery.Where(p=>p.SalariedFlag ==0)
                       .OrderBy(tran => tran.BusinessEntityID);

var finalResult = queryOne.Union(queryTwo);

Source