从上a.BranchKey AllBranchKeys一个在AllOrders 
 JOIN b  VAR OrdersByBranches = 
等于b.BranchKey 
排序依据a.Date 
通过新的{a.Date，a.paymentMethod}成BranchOrderGrouped 
组中选择新的{
 BranchOrderGrouped.Key.Date，
 CurrencyAmount = BranchOrderGrouped.Sum（A => a.CurrencyAmount） ，
 BranchOrderGrouped.Key.paymentMethod 
}; 

如果（string.IsNullOrEmpty（BranchKeySelected））
 {
 OrdersByBranches = OrdersByBranches.Where（/ * * blbabla /）; 
} 

返回OrdersByBranches; 
 

I am new to LINQ so apologises upfront

I have the following Linq query :-

var OrdersByBranches =
    from a in AllOrders
    join b in AllBranchKeys
        on a.BranchKey equals b.BranchKey
    orderby a.Date
    group a by new { a.Date, a.paymentMethod } into BranchOrderGrouped
    select new
    {
        BranchOrderGrouped.Key.Date,
        CurrencyAmount = BranchOrderGrouped.Sum(a =>
        a.CurrencyAmount),
        BranchOrderGrouped.Key.paymentMethod
    };

I need to include a where clause in the above query ... only if a variable called BranchKeySelected is ""

I have tried using an If Else statement and have the same above query duplicated with one containing a where clause and one NOT. ...But When I do this .. then OrdersByBranches is NOT available outside of the IF Statement

Would be grateful for any help

Regards

Ghost

var OrdersByBranches = 
    from a in AllOrders 
    join b in AllBranchKeys on a.BranchKey equals b.BranchKey 
    orderby a.Date 
    group a by new { a.Date, a.paymentMethod } into BranchOrderGrouped 
    select new { 
        BranchOrderGrouped.Key.Date, 
        CurrencyAmount = BranchOrderGrouped.Sum(a =>  a.CurrencyAmount), 
        BranchOrderGrouped.Key.paymentMethod 
    };

if(string.IsNullOrEmpty(BranchKeySelected ))
{
    OrdersByBranches = OrdersByBranches.Where(/*blbabla*/);
}

return OrdersByBranches;