DataTable.CaseSensitive Propiedad

Definición

Espacio de nombres:

System.Data

Ensamblado:

System.Data.Common.dll

Source:

DataTable.cs

Indica si las comparaciones de cadenas en la tabla distinguen entre mayúsculas y minúsculas.

public:
 property bool CaseSensitive { bool get(); void set(bool value); };

public bool CaseSensitive { get; set; }

member this.CaseSensitive : bool with get, set

Public Property CaseSensitive As Boolean

Valor de propiedad

Boolean

true si la comparación distingue entre mayúsculas y minúsculas; de lo contrario, false. El valor predeterminado se establece en la propiedad DataSet del objeto CaseSensitive primario, o bien en false si DataTable se ha creado independientemente de DataSet.

Ejemplos

En el ejemplo siguiente se llama al Select método dos veces en .DataTable La primera vez, la CaseSensitive propiedad se establece en false, la segunda, en true.

private static void ToggleCaseSensitive()
{
    DataTable t;
    DataRow[] foundRows;

    t = CreateDataSet().Tables[0];

    t.CaseSensitive = false;
    foundRows = t.Select("item = 'abc'");

    // Print out DataRow values.
    PrintRowValues(foundRows, "CaseSensitive = False");

    t.CaseSensitive = true;
    foundRows = t.Select("item = 'abc'");

    PrintRowValues(foundRows, "CaseSensitive = True");
}

public static DataSet CreateDataSet()
{
    // Create a DataSet with one table, two columns
    DataSet ds = new DataSet();
    DataTable t = new DataTable("Items");

    // Add table to dataset
    ds.Tables.Add(t);

    // Add two columns
    DataColumn c;

    // First column
    c = t.Columns.Add("id", typeof(int));
    c.AutoIncrement = true;

    // Second column
    t.Columns.Add("item", typeof(string));

    // Set primary key
    t.PrimaryKey = new DataColumn[] { t.Columns["id"] };

    // Add twelve rows
    for (int i = 0; i < 10; i++)
    {
        t.Rows.Add(new object[] { i, i.ToString() });
    }
    t.Rows.Add(new object[] { 11, "abc" });
    t.Rows.Add(new object[] { 15, "ABC" });

    return ds;
}

private static void PrintRowValues(DataRow[] rows, string label)
{
    Console.WriteLine();
    Console.WriteLine(label);
    if (rows.Length <= 0)
    {
        Console.WriteLine("no rows found");
        return;
    }
    foreach (DataRow r in rows)
    {
        foreach (DataColumn c in r.Table.Columns)
        {
            Console.Write("\t {0}", r[c]);
        }
        Console.WriteLine();
    }
}

Private Sub ToggleCaseSensitive()
    Dim t As DataTable
    Dim foundRows() As DataRow

    t = CreateDataSet().Tables(0)

    t.CaseSensitive = False
    foundRows = t.Select("item = 'abc'")

    ' Print out DataRow values. Row 0 contains the value we're looking for.
    PrintRowValues(foundRows, "CaseSensitive = False")

    t.CaseSensitive = True
    foundRows = t.Select("item = 'abc'")

    PrintRowValues(foundRows, "CaseSensitive = True")
End Sub

Public Function CreateDataSet() As DataSet
    ' Create a DataSet with one table, two columns
    Dim ds As New DataSet
    Dim t As New DataTable("Items")

    ' Add table to DataSet
    ds.Tables.Add(t)

    ' Add two columns
    Dim c As DataColumn

    ' First column
    c = t.Columns.Add("id", Type.GetType("System.Int32"))
    c.AutoIncrement = True

    ' Second column
    t.Columns.Add("item", Type.GetType("System.String"))

    ' Set primary key
    t.PrimaryKey = New DataColumn() {t.Columns("id")}

    For i As Integer = 0 To 9
        t.Rows.Add(New Object() {i, i.ToString()})
    Next
    t.Rows.Add(New Object() {11, "abc"})
    t.Rows.Add(New Object() {15, "ABC"})

    CreateDataSet = ds
End Function

Private Sub PrintRowValues(ByRef rows As DataRow(), ByVal label As String)
    Console.WriteLine()
    Console.WriteLine(label)
    If rows.Length <= 0 Then
        Console.WriteLine("no rows found")
        Return
    End If

    For Each r As DataRow In rows
        For Each c As DataColumn In r.Table.Columns
            Console.Write(vbTab & " {0}", r(c))
        Next
        Console.WriteLine()
    Next
End Sub

Comentarios

La CaseSensitive propiedad afecta a las comparaciones de cadenas en la ordenación, la búsqueda y el filtrado.

Consulte también

• Select()
• Objetos DataTable