Filtering DataSet
I have a DataSet full of costumers. I was wondering if there is any way to filter the dataset and only get the informa开发者_如何学运维tion I want. For example, to get CostumerName
and CostumerAddress
for a costumer that has CostumerID = 1
Is it possible?
You can use DataTable.Select
:
var strExpr = "CostumerID = 1 AND OrderCount > 2";
var strSort = "OrderCount DESC";
// Use the Select method to find all rows matching the filter.
foundRows = ds.Table[0].Select(strExpr, strSort);
Or you can use DataView
:
ds.Tables[0].DefaultView.RowFilter = strExpr;
UPDATE I'm not sure why you want to have a DataSet returned. But I'd go with the following solution:
var dv = ds.Tables[0].DefaultView;
dv.RowFilter = strExpr;
var newDS = new DataSet();
var newDT = dv.ToTable();
newDS.Tables.Add(newDT);
No mention of Merge?
DataSet newdataset = new DataSet();
newdataset.Merge( olddataset.Tables[0].Select( filterstring, sortstring ));
The above were really close. Here's my solution:
Private Sub getDsClone(ByRef inClone As DataSet, ByVal matchStr As String, ByRef outClone As DataSet)
Dim i As Integer
outClone = inClone.Clone
Dim dv As DataView = inClone.Tables(0).DefaultView
dv.RowFilter = matchStr
Dim dt As New DataTable
dt = dv.ToTable
For i = 0 To dv.Count - 1
outClone.Tables(0).ImportRow(dv.Item(i).Row)
Next
End Sub
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