wpf 比较两个数据表并在 LINQ 中显示另一个数据表中的差异
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Compare two DataTables and Display the differences in another datatable in LINQ
提问by Lakshminarayanan E
I have two DataTables and I want to display the rows. if both the datatables having the same value, Then mark X in all columns or else select the column with highest value(Eg:DT1: 10,DT2 :5)
我有两个数据表，我想显示行。如果两个数据表具有相同的值，则在所有列中标记 X 或选择具有最高值的列（例如：DT1：10，DT2：5）
Datatable1
数据表1
id Name Weight
1 Ship 500
2 Train 600
3 Plane 700
4 Car 800
Datatable2
数据表2
id Name Weight
1 Ship 500
3 Plane 600
4 Car 200
I want the result to be:
我希望结果是：
Datatable3
数据表3
id Name Weight Datatable1 Datatable2
1 Ship 500 X X
2 Train 600 X
3 Plane 700 X X
4 Car 800 X
I have tried the below:-
我尝试了以下方法：-
DataTable Datatable3 = (from a in Datatable1.AsEnumerable()
join b in Datatable2.AsEnumerable()
on a["Name"].ToString() equals b["Name"].ToString()
a["Weight"].ToString() equals b["Weight"].ToString() into g
where g.Count() != 1 select a).CopyToDataTable();
dataGrid1.ItemsSource = Datatable3.DefaultView;
Please help me on this. Thanks in advance
请帮我解决这个问题。提前致谢
回答by Rahul Singh
This is what I have:-
这就是我所拥有的：-
DataTable Datatable3 = dt1.AsEnumerable().Union(dt2.AsEnumerable())
.GroupBy(x => x.Field<int>("Id"))
.Select(x =>
{
var topWeightItem = x.OrderByDescending(z => z.Field<int> ("Weight")).First();
return new Items
{
Id = x.Key,
Name = topWeightItem.Field<string>("Name"),
Weight = topWeightItem.Field<int>("Weight"),
DataTable1 = dt1.AsEnumerable().Any(z => z.Field<int>("Id") == x.Key
&& z.Field<int>("Weight") == topWeightItem.Field<int>("Weight")
&& z.Field<string>("Name") == topWeightItem.Field<string>("Name"))
? "X" : String.Empty,
DataTable2 = dt2.AsEnumerable().Any(z => z.Field<int>("Id") == x.Key
&& z.Field<int>("Weight") == topWeightItem.Field<int>("Weight")
&& z.Field<string>("Name") == topWeightItem.Field<string>("Name"))
? "X" : String.Empty
};
}
).PropertiesToDataTable<Items>();
Since It is returning an anonymoustype, you can't use CopyToDataTablemethod, so please check thisto understand how I converted it into a datatable.
由于它返回一个anonymous类型，你不能使用CopyToDataTable方法，所以请检查这个以了解我如何将它转换为数据表。
I am getting this output:-
我得到这个输出：-
I have used following type for conversion purpose:-
我使用以下类型进行转换：-
public class Items
{
public int Id { get; set; }
public string Name { get; set; }
public decimal Weight { get; set; }
public string DataTable1 { get; set; }
public string DataTable2 { get; set; }
}
回答by Asif Iqbal
I have written in two query to achieve what you said..Perhaps you can optimize it further.
我写了两个查询来实现你所说的......也许你可以进一步优化它。
//datatable1
DataTable dt1 = new DataTable();
dt1.Columns.Add("Id");
dt1.Columns.Add("Name");
dt1.Columns.Add("Weight");
DataRow dr ;
dr = dt1.NewRow();
dr["Id"] = 1;
dr["Name"] = "Ship";
dr["Weight"] = 500;
dt1.Rows.Add(dr);
dr = dt1.NewRow();
dr["Id"] = 2;
dr["Name"] = "Train";
dr["Weight"] = 600;
dt1.Rows.Add(dr);
dr = dt1.NewRow();
dr["Id"] = 3;
dr["Name"] = "Plane";
dr["Weight"] = 700;
dt1.Rows.Add(dr);
dr = dt1.NewRow();
dr["Id"] = 4;
dr["Name"] = "Car";
dr["Weight"] = 400;
dt1.Rows.Add(dr);
//datatable2
DataTable dt2 = new DataTable();
dt2.Columns.Add("Id");
dt2.Columns.Add("Name");
dt2.Columns.Add("Weight");
DataRow dr2;
dr2 = dt2.NewRow();
dr2["Id"] = 1;
dr2["Name"] = "Ship";
dr2["Weight"] = 500;
dt2.Rows.Add(dr2);
dr2 = dt2.NewRow();
dr2["Id"] = 3;
dr2["Name"] = "Plane";
dr2["Weight"] = 700;
dt2.Rows.Add(dr2);
dr2 = dt2.NewRow();
dr2["Id"] = 4;
dr2["Name"] = "Car";
dr2["Weight"] = 400;
dt2.Rows.Add(dr2);
//iterate through table1
IEnumerable<DataRow> table1 = from r in dt1.AsEnumerable()
select r;
//iterate through table2
IEnumerable<DataRow> table2 = from r in dt2.AsEnumerable()
select r;
Console.WriteLine("Id\tName\tWeight\tDatatable1\tDatatable2");
Console.WriteLine("----------------------------------------------------");
//prints the common records
foreach (DataRow td1 in table1.Distinct())//Matches wholes of the Element Sequence inside IEnumerable
{
table2.Distinct().ToList().ForEach(td2 =>
{
if (td1.Field<string>("Id") == td2.Field<string>("Id"))
{
Console.WriteLine(td1.Field<string>("Id") + "\t" + td1.Field<string>("Name") + "\t" + td1.Field<string>("Weight") + "\t" + "x" + "\t\t" + "x");
}
});
}
//prints the missing records
var query = (from tb1 in dt1.AsEnumerable()
join tb2 in dt2.AsEnumerable()
on tb1.Field<string>("Id") equals tb2.Field<string>("Id") into subset
from sc in subset.DefaultIfEmpty()
where sc == null
select new
{
id = tb1.Field<string>("Id"),
name = tb1.Field<string>("Name"),
wt = tb1.Field<string>("Weight")
}).Distinct();
foreach (var td1 in query)
{
Console.WriteLine(td1.id + "\t" + td1.name + "\t" + td1.wt + "\t" + "x" + "\t\t" + "-");
}
