DataTable.Select Method (String, String, DataViewRowState)
.NET Framework (current version)
Gets an array of all DataRow objects that match the filter in the order of the sort that match the specified state.
Assembly: System.Data (in System.Data.dll)
Public Function Select ( filterExpression As String, sort As String, recordStates As DataViewRowState ) As DataRow()
Parameters
- filterExpression
-
Type:
System.String
The criteria to use to filter the rows. For examples on how to filter rows, see DataView RowFilter Syntax [C#].
- sort
-
Type:
System.String
A string specifying the column and sort direction.
- recordStates
-
Type:
System.Data.DataViewRowState
One of the DataViewRowState values.
To form the filterExpression argument, use the same rules for creating the DataColumn class's Expression property value. The Sort argument also uses the same rules for creating class's Expression strings.
If the column on the filter contains a null value, it will not be part of the result.
The following example uses a filter expression and record state to return an array of DataRow objects.
Private Sub GetRowsByFilter() Dim customerTable As DataTable = New DataTable("Customers") ' Add columns customerTable.Columns.Add("id", GetType(Integer)) customerTable.Columns.Add("name", GetType(String)) ' Set PrimaryKey customerTable.Columns("id").Unique = True customerTable.PrimaryKey = New DataColumn() _ {customerTable.Columns("id")} ' add ten rows Dim id As Integer For id = 1 To 10 customerTable.Rows.Add( _ New Object() {id, String.Format("customer{0}", id)}) Next id customerTable.AcceptChanges() ' add another ten rows For id = 11 To 20 customerTable.Rows.Add( _ New Object() {id, String.Format("customer{0}", id)}) Next id Dim expression As String Dim sortOrder As String expression = "id > 5" ' Sort descending by CompanyName column. sortOrder = "name DESC" ' Use the Select method to find all rows matching the filter. Dim foundRows As DataRow() = _ customerTable.Select(expression, sortOrder, _ DataViewRowState.Added) PrintRows(foundRows, "filtered rows") foundRows = customerTable.Select() PrintRows(foundRows, "all rows") End Sub Private Sub PrintRows(ByVal rows() As DataRow, ByVal label As String) Console.WriteLine("\n{0}", label) If rows.Length <= 0 Then Console.WriteLine("no rows found") Exit Sub End If Dim row As DataRow Dim column As DataColumn For Each row In rows For Each column In row.Table.Columns Console.Write("\table {0}", row(column)) Next column Console.WriteLine() Next row End Sub
.NET Framework
Available since 1.1
Available since 1.1
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