DataSet.EnforceConstraints DataSet.EnforceConstraints DataSet.EnforceConstraints DataSet.EnforceConstraints Property

Definición

Obtiene o establece un valor que indica si se siguen las reglas de restricción al intentar realizar cualquier operación de actualización.Gets or sets a value indicating whether constraint rules are followed when attempting any update operation.

public:
 property bool EnforceConstraints { bool get(); void set(bool value); };
[System.Data.DataSysDescription("DataSetEnforceConstraintsDescr")]
public bool EnforceConstraints { get; set; }
member this.EnforceConstraints : bool with get, set
Public Property EnforceConstraints As Boolean

Valor de propiedad

trueSi se aplican las reglas; en caso falsecontrario,.true if rules are enforced; otherwise, false. De manera predeterminada, es true.The default is true.

Excepciones

No se pueden forzar una o más restricciones.One or more constraints cannot be enforced.

Ejemplos

En el ejemplo siguiente se DataSet crea un con una tabla, una columna, cinco filas y UniqueConstraintuna.The following example creates a DataSet with one table, one column, five rows, and one UniqueConstraint. La EnforceConstraints propiedad se establece en false y los valores de cada fila se establecen en el mismo valor.The EnforceConstraints property is set to false and the values of each row are set to the same value. Cuando se EnforceConstraints restablece la propiedad a true, se ConstraintException genera un.When the EnforceConstraints property is reset to true, a ConstraintException is generated.

private void DemonstrateEnforceConstraints()
{
    // Create a DataSet with one table, one column and 
    // a UniqueConstraint.
    DataSet dataSet= new DataSet("dataSet");
    DataTable table = new DataTable("table");
    DataColumn column = new DataColumn("col1");

    // A UniqueConstraint is added when the Unique 
    // property is true.
    column.Unique=true;
    table.Columns.Add(column);
    dataSet.Tables.Add(table);
    Console.WriteLine("constraints.count: " + 
        table.Constraints.Count);

    // add five rows.
    DataRow row ;
    for(int i=0;i<5;i++)
    {
        row = table.NewRow();
        row["col1"] = i;
        table.Rows.Add(row);
    }
    table.AcceptChanges();

    dataSet.EnforceConstraints=false;
    // Change the values of all rows to 1.
    foreach(DataRow thisRow in table.Rows)
    {
        thisRow["col1"]=1;
        //Console.WriteLine("\table" + thisRow[0]);
    }
    try
    {
        dataSet.EnforceConstraints=true;
    }
    catch(System.Data.ConstraintException e)
    {
        // Process exception and return.
        Console.WriteLine("Exception of type {0} occurred.", 
            e.GetType());
    }
}
Private Sub DemonstrateEnforceConstraints()
    ' Create a DataSet with one table, one column and 
    ' a UniqueConstraint.
    Dim dataSet As New DataSet("dataSet")
    Dim table As New DataTable("table")
    Dim column As New DataColumn("col1")
    column.Unique = True
    table.Columns.Add(column)
    dataSet.Tables.Add(table)
    Console.WriteLine("constraints.count: " _
        & table.Constraints.Count)

    ' add five rows.
    Dim row As DataRow
    Dim i As Integer
    For i = 0 To 4
       row = table.NewRow()
       row("col1") = i
       table.Rows.Add(row)
    Next
    table.AcceptChanges()
     
    dataSet.EnforceConstraints = False
    ' Change the values of all rows to 1.
    Dim thisRow As DataRow
    For Each thisRow In table.rows
       thisRow("col1") = 1
    Next
 
    Try
        dataSet.EnforceConstraints = True
    Catch e As System.Data.ConstraintException
	    ' Process exception and return.
        Console.WriteLine("Exception of type {0} occurred.", _
            e.GetType().ToString())
    End Try
End Sub

Comentarios

Las restricciones se establecen en el DataTable nivel (Constraints propiedad).Constraints are set at the DataTable level (Constraints property). Para obtener más información sobre cómo crear restricciones, vea restricciones de DataTable.For more information about creating constraints, see DataTable Constraints.

Se aplica a

Consulte también: