DataTable.Select DataTable.Select DataTable.Select DataTable.Select Method

Definición

Obtiene una matriz de DataRow objetos.Gets an array of DataRow objects.

Sobrecargas

Select() Select() Select() Select()

Obtiene una matriz de todos los objetos DataRow.Gets an array of all DataRow objects.

Select(String) Select(String) Select(String) Select(String)

Obtiene una matriz de todos los objetos DataRow que coinciden con los criterios de filtro.Gets an array of all DataRow objects that match the filter criteria.

Select(String, String) Select(String, String) Select(String, String) Select(String, String)

Obtiene una matriz de todos los objetos DataRow que coinciden con los criterios de filtro, en el criterio de ordenación especificado.Gets an array of all DataRow objects that match the filter criteria, in the specified sort order.

Select(String, String, DataViewRowState) Select(String, String, DataViewRowState) Select(String, String, DataViewRowState) Select(String, String, DataViewRowState)

Obtiene una matriz de todos los objetos DataRow que coinciden con el filtro en el orden de clasificación y que coinciden con el estado especificado.Gets an array of all DataRow objects that match the filter in the order of the sort that match the specified state.

Select() Select() Select() Select()

Obtiene una matriz de todos los objetos DataRow.Gets an array of all DataRow objects.

public:
 cli::array <System::Data::DataRow ^> ^ Select();
public System.Data.DataRow[] Select ();
member this.Select : unit -> System.Data.DataRow[]
Public Function Select () As DataRow()

Devoluciones

Matriz de objetos DataRow.An array of DataRow objects.

Ejemplos

El ejemplo siguiente devuelve una matriz de DataRow objetos a través de la Select método.The following example returns an array of DataRow objects through the Select method.

private void GetRows()
{
    // Get the DataTable of a DataSet.
    DataTable table = DataSet1.Tables["Suppliers"];
    DataRow[] rows = table.Select();

    // Print the value one column of each DataRow.
    for(int i = 0; i < rows.Length ; i++)
    {
        Console.WriteLine(rows[i]["CompanyName"]);
    }
}
Private Sub GetRows()
    ' Get the DataTable of a DataSet.
    Dim table As DataTable = DataSet1.Tables("Suppliers")
    Dim rows() As DataRow = table.Select()

    Dim i As Integer
    ' Print the value one column of each DataRow.
    For i = 0 to rows.GetUpperBound(0)
       Console.WriteLine(rows(i)("CompanyName"))
    Next i
End Sub

Comentarios

Para asegurarse de que el criterio de ordenación adecuado, especificar los criterios de ordenación con Select(String, String) o Select(String, String, DataViewRowState).To ensure the proper sort order, specify sort criteria with Select(String, String) or Select(String, String, DataViewRowState).

Consulte también:

Select(String) Select(String) Select(String) Select(String)

Obtiene una matriz de todos los objetos DataRow que coinciden con los criterios de filtro.Gets an array of all DataRow objects that match the filter criteria.

public:
 cli::array <System::Data::DataRow ^> ^ Select(System::String ^ filterExpression);
public System.Data.DataRow[] Select (string filterExpression);
member this.Select : string -> System.Data.DataRow[]
Public Function Select (filterExpression As String) As DataRow()

Parámetros

filterExpression
String String String String

Criterios que se van a utilizar para filtrar las filas.The criteria to use to filter the rows. Para obtener ejemplos sobre cómo filtrar filas, vea DataView RowFilter Syntax [C#] (Sintaxis de DataView RowFilter [C#]).For examples on how to filter rows, see DataView RowFilter Syntax [C#].

Devoluciones

Matriz de objetos DataRow.An array of DataRow objects.

Ejemplos

En el ejemplo siguiente se usa una expresión de filtro para devolver una matriz de DataRow objetos.The following example uses a filter expression to return an array of DataRow objects.

private void GetRowsByFilter()
{
    DataTable table = DataSet1.Tables["Orders"];
    // Presuming the DataTable has a column named Date.
    string expression;
    expression = "Date > #1/1/00#";
    DataRow[] foundRows;

    // Use the Select method to find all rows matching the filter.
    foundRows = table.Select(expression);

    // Print column 0 of each returned row.
    for(int i = 0; i < foundRows.Length; i ++)
    {
        Console.WriteLine(foundRows[i][0]);
    }
}
Private Sub GetRowsByFilter()
    
    Dim table As DataTable = DataSet1.Tables("Orders")

    ' Presuming the DataTable has a column named Date.
    Dim expression As String
    expression = "Date > #1/1/00#"
    Dim foundRows() As DataRow

    ' Use the Select method to find all rows matching the filter.
    foundRows = table.Select(expression)

    Dim i As Integer
    ' Print column 0 of each returned row.
    For i = 0 to foundRows.GetUpperBound(0)
       Console.WriteLine(foundRows(i)(0))
    Next i
End Sub

Comentarios

Para crear el filterExpression argumento, use las mismas reglas que se aplican a la DataColumn la clase Expression valor de propiedad para la creación de filtros.To create the filterExpression argument, use the same rules that apply to the DataColumn class's Expression property value for creating filters.

Para asegurarse de que el criterio de ordenación adecuado, especificar los criterios de ordenación con Select(String, String) o Select(String, String, DataViewRowState).To ensure the proper sort order, specify sort criteria with Select(String, String) or Select(String, String, DataViewRowState).

Si la columna en el filtro contiene un valor null, no será parte del resultado.If the column on the filter contains a null value, it will not be part of the result.

Consulte también:

Select(String, String) Select(String, String) Select(String, String) Select(String, String)

Obtiene una matriz de todos los objetos DataRow que coinciden con los criterios de filtro, en el criterio de ordenación especificado.Gets an array of all DataRow objects that match the filter criteria, in the specified sort order.

public:
 cli::array <System::Data::DataRow ^> ^ Select(System::String ^ filterExpression, System::String ^ sort);
public System.Data.DataRow[] Select (string filterExpression, string sort);
member this.Select : string * string -> System.Data.DataRow[]
Public Function Select (filterExpression As String, sort As String) As DataRow()

Parámetros

filterExpression
String String String String

Criterios que se van a utilizar para filtrar las filas.The criteria to use to filter the rows. Para obtener ejemplos sobre cómo filtrar filas, vea DataView RowFilter Syntax [C#] (Sintaxis de DataView RowFilter [C#]).For examples on how to filter rows, see DataView RowFilter Syntax [C#].

sort
String String String String

Cadena que especifica la columna y orden de clasificación.A string specifying the column and sort direction.

Devoluciones

Matriz de objetos DataRow que coinciden con la expresión de filtro.An array of DataRow objects matching the filter expression.

Ejemplos

En el ejemplo siguiente se usa una expresión de filtro para devolver una matriz de DataRow objetos.The following example uses a filter expression to return an array of DataRow objects.

using System;
using System.Data;

public class A {  

   public static void Main() {      
      DataTable table = new DataTable("Orders");
      table.Columns.Add("OrderID", typeof(Int32));
      table.Columns.Add("OrderQuantity", typeof(Int32));
      table.Columns.Add("CompanyName", typeof(string));      
      table.Columns.Add("Date", typeof(DateTime));

      DataRow newRow = table.NewRow();
      newRow["OrderID"] = 1;
      newRow["OrderQuantity"] = 3;
      newRow["CompanyName"] = "NewCompanyName";
      newRow["Date"] = "1979, 1, 31";

      // Add the row to the rows collection.
      table.Rows.Add(newRow);
      
      DataRow newRow2 = table.NewRow();
      newRow2["OrderID"] = 2;
      newRow2["OrderQuantity"] = 2;
      newRow2["CompanyName"] = "NewCompanyName1";
      table.Rows.Add(newRow2);

      DataRow newRow3 = table.NewRow();
      newRow3["OrderID"] = 3;
      newRow3["OrderQuantity"] = 2;
      newRow3["CompanyName"] = "NewCompanyName2";
      table.Rows.Add(newRow3);

      // Presuming the DataTable has a column named Date.
      string expression = "Date = '1/31/1979' or OrderID = 2";
      // string expression = "OrderQuantity = 2 and OrderID = 2";

      // Sort descending by column named CompanyName.
      string sortOrder = "CompanyName ASC";
      DataRow[] foundRows;

      // Use the Select method to find all rows matching the filter.
      foundRows = table.Select(expression, sortOrder);

      // Print column 0 of each returned row.
      for (int i = 0; i < foundRows.Length; i++)
         Console.WriteLine(foundRows[i][2]);
   }
}
Imports System.Data

Public Class A

   Public Shared Sub Main()
      Dim table As New DataTable("Orders")
      table.Columns.Add("OrderID", GetType(Int32))
      table.Columns.Add("OrderQuantity", GetType(Int32))
      table.Columns.Add("CompanyName", GetType(String))
      table.Columns.Add("Date", GetType(DateTime))

      Dim newRow As DataRow = table.NewRow()
      newRow("OrderID") = 1
      newRow("OrderQuantity") = 3
      newRow("CompanyName") = "NewCompanyName"
      newRow("Date") = "1979, 1, 31"

      ' Add the row to the rows collection.
      table.Rows.Add(newRow)

      Dim newRow2 As DataRow = table.NewRow()
      newRow2("OrderID") = 2
      newRow2("OrderQuantity") = 2
      newRow2("CompanyName") = "NewCompanyName1"
      table.Rows.Add(newRow2)

      Dim newRow3 As DataRow = table.NewRow()
      newRow3("OrderID") = 3
      newRow3("OrderQuantity") = 2
      newRow3("CompanyName") = "NewCompanyName2"
      table.Rows.Add(newRow3)

      ' Presuming the DataTable has a column named Date.
      Dim expression As String = "Date = '1/31/1979' or OrderID = 2"
      ' Dim expression As String = "OrderQuantity = 2 and OrderID = 2"

      ' Sort descending by column named CompanyName.
      Dim sortOrder As String = "CompanyName ASC"
      Dim foundRows As DataRow()

      ' Use the Select method to find all rows matching the filter.
      foundRows = table.[Select](expression, sortOrder)

      ' Print column 0 of each returned row.
      For i As Integer = 0 To foundRows.Length - 1
         Console.WriteLine(foundRows(i)(2))
      Next
   End Sub
End Class

Comentarios

Para formar el filterExpression argumento, usar las mismas reglas para crear el DataColumn la clase Expression valor de propiedad.To form the filterExpression argument, use the same rules for creating the DataColumn class's Expression property value. El Sort argumento también usa las mismas reglas para la creación de la clase Expression cadenas.The Sort argument also uses the same rules for creating class's Expression strings.

Si la columna en el filtro contiene un valor null, no será parte del resultado.If the column on the filter contains a null value, it will not be part of the result.

Consulte también:

Select(String, String, DataViewRowState) Select(String, String, DataViewRowState) Select(String, String, DataViewRowState) Select(String, String, DataViewRowState)

Obtiene una matriz de todos los objetos DataRow que coinciden con el filtro en el orden de clasificación y que coinciden con el estado especificado.Gets an array of all DataRow objects that match the filter in the order of the sort that match the specified state.

public:
 cli::array <System::Data::DataRow ^> ^ Select(System::String ^ filterExpression, System::String ^ sort, System::Data::DataViewRowState recordStates);
public System.Data.DataRow[] Select (string filterExpression, string sort, System.Data.DataViewRowState recordStates);
member this.Select : string * string * System.Data.DataViewRowState -> System.Data.DataRow[]
Public Function Select (filterExpression As String, sort As String, recordStates As DataViewRowState) As DataRow()

Parámetros

filterExpression
String String String String

Criterios que se van a utilizar para filtrar las filas.The criteria to use to filter the rows. Para obtener ejemplos sobre cómo filtrar filas, vea DataView RowFilter Syntax [C#] (Sintaxis de DataView RowFilter [C#]).For examples on how to filter rows, see DataView RowFilter Syntax [C#].

sort
String String String String

Cadena que especifica la columna y orden de clasificación.A string specifying the column and sort direction.

Devoluciones

Matriz de objetos DataRow.An array of DataRow objects.

Ejemplos

En el ejemplo siguiente se usa una expresión y el registro de estado del filtro para devolver una matriz de DataRow objetos.The following example uses a filter expression and record state to return an array of DataRow objects.

private static void GetRowsByFilter()
{
    DataTable customerTable = new DataTable("Customers");
    // Add columns
    customerTable.Columns.Add("id", typeof(int));
    customerTable.Columns.Add("name", typeof(string));

    // Set PrimaryKey
    customerTable.Columns[ "id" ].Unique = true;
    customerTable.PrimaryKey = new DataColumn[] 
        { customerTable.Columns["id"] };

    // Add ten rows
    for(int id=1; id<=10; id++)
    {
        customerTable.Rows.Add(
            new object[] { id, string.Format("customer{0}", id) });
    }
    customerTable.AcceptChanges();

    // Add another ten rows
    for(int id=11; id<=20; id++)
    {
        customerTable.Rows.Add(
            new object[] { id, string.Format("customer{0}", id) });
    }

    string expression;
    string sortOrder;

    expression = "id > 5";
    // Sort descending by column named CompanyName.
    sortOrder = "name DESC";
    // Use the Select method to find all rows matching the filter.
    DataRow[] foundRows = 
        customerTable.Select(expression, sortOrder, 
        DataViewRowState.Added);

    PrintRows(foundRows, "filtered rows");

    foundRows = customerTable.Select();
    PrintRows(foundRows, "all rows");
}

private static void PrintRows(DataRow[] rows, string label)
{
    Console.WriteLine("\n{0}", label);
    if(rows.Length <= 0)
    {
        Console.WriteLine("no rows found");
        return;
    }
    foreach(DataRow row in rows)
    {
        foreach(DataColumn column in row.Table.Columns)
        {
            Console.Write("\table {0}", row[column]);
        }
        Console.WriteLine();
    }
}
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

Comentarios

Para formar el filterExpression argumento, usar las mismas reglas para crear el DataColumn la clase Expression valor de propiedad.To form the filterExpression argument, use the same rules for creating the DataColumn class's Expression property value. El Sort argumento también usa las mismas reglas para la creación de la clase Expression cadenas.The Sort argument also uses the same rules for creating class's Expression strings.

Si la columna en el filtro contiene un valor null, no será parte del resultado.If the column on the filter contains a null value, it will not be part of the result.

Consulte también:

Se aplica a