Add values from two datatypes to new datatable
I have two strongly typed Datatable ( dt1
):
|FirstName|LastName|Val1|Val2|
|Tony |Stark |34 |35 |
|Steve |Rogers |12 |23 |
|Natasha |Romanoff|2 |100 |
and the second ( dt2
)
|FirstName|LastName|Val1|Val2|
|Tony |Stark |16 |5 |
|Bruce |Banner |2 |1 |
|Steve |Rogers |54 |40 |
I am trying to create a new Datatable where I add values for people. I need an outer join as I need all the people and the value in the second table is cut in half.
So, the result should look like this:
|FirstName|LastName|Val1|Val2|
|Tony |Stark |42 |37.5|
|Steve |Rogers |39 |43 |
|Natasha |Romanoff|2 |100 |
|Bruce |Banner |1 |0.5 |
My approach was with LINQ:
Dim query =
from a in ds1.Table1
Join b in ds2.Table2
On a.FirstName + a.LastName Equals b.FirstName + b.Lastname
Select New With {
.FirstName = a.FirstName,
.LastName = a.LastName,
.Val1 = a.Val1 + b.Val1 *0.5,
.Val2 = a.Val2 + b.Val2 *0.5
}
But I don't understand all people with an approach. I have also tried
Dim query =
From a in ds1.Table1
From b in ds2.Table2
Select New With{
Key .KeyName = a.FirstName + a.LastName = b.FirstName + b.FirstName,
.Val1 = a.Val1 + b.Val1 *0.5,
.Val2 = a.Val2 + b.Val2 * 0.5
}
Now I get a lot of entries for each person. Can anyone help me to do this. I don't know if there is another non-Linq approach to solve this problem.
source to share
An example using group by
. The fact is that before performing operations group by
, Sum
all values in the second table must be divided by 2. I will take care of this before.Concat
var dt1 = new List<MyClass>();
dt1.Add(new MyClass { FirstName = "Tony", LastName = "Stark", Val1 = 34, Val2 = 35});
dt1.Add(new MyClass { FirstName = "Steve", LastName = "Rogers", Val1 = 12, Val2 = 23});
dt1.Add(new MyClass { FirstName = "Natasha", LastName = "Romanoff", Val1 = 2, Val2 = 100 });
var dt2 = new List<MyClass>();
dt2.Add(new MyClass { FirstName = "Tony", LastName = "Stark", Val1 = 16, Val2 = 5 });
dt2.Add(new MyClass { FirstName = "Bruce", LastName = "Banner", Val1 = 2, Val2 = 1 });
dt2.Add(new MyClass { FirstName = "Steve", LastName = "Rogers", Val1 = 54, Val2 = 40 });
var q = from a in dt1
.Concat(
from b in dt2
select new MyClass
{
FirstName = b.FirstName,
LastName = b.LastName,
Val1 = b.Val1 * 0.5m,
Val2 = b.Val2 * 0.5m
})
group a by new {a.FirstName, a.LastName}
into g
select new
{
g.First().FirstName,
g.First().LastName,
Val1 = g.Sum(x => x.Val1),
Val2 = g.Sum(x => x.Val2),
};
foreach (var s in q)
{
Console.WriteLine("{0} {1} {2} {3}", s.FirstName,s.LastName,s.Val1,s.Val2);
}
Result
Tony Stark 42,0 37,5
Steve Rogers 39,0 43,0
Natasha Romanoff 2 100
Bruce Banner 1,0 0,5
source to share
I got it now. My decision:
Dim qLeft = From a in dt1.Getdt1Info
Group Join b in dt2.Getdt2Info
On a.FirstName + a.LastName Equals b.FirstName + b.LastName
Into NewGroup = Group
From c in NewGroup.DefaultIfEmpty
Select New With{
.Name = a.FirstName + ", " + a.LastName,
.Value1 = a.Val1 + If (c is nothing, 0D, c.Val1) * 0.5,
.Value2 = a.Val2 + If (c is nothing, 0D, c.Val2) * 0.5
}
Dim qRight =From a in dt2.Getdt2Info
Group Join b in dt1.Getdt1Info
On a.FirstName + a.LastName Equals b.FirstName + b.LastName
Into NewGroup = Group
From c in NewGroup.DefaultIfEmpty
Select New With{
.Name = a.FirstName + ", " + a.LastName,
.Value1 = a.val1 * 0.5 + If (c Is Nothing, 0D, c.Val1),
.Value2 = a.val2 * 0.5 + If (c Is Nothing, 0d, c.Val2)}
Dim qFull = qleft.Concat(qRight).GroupBy(function(x) x.Name).Select(function(x) x.First)
I still don't know why qleft.Union (qRight) doesn't remove duplicates. I solved it with functions (s. Code).
source to share