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Classe SafeToPrepareAttribute

Marks the methods in the assembly that are safe to run with the ExecuteForPrepare property set to true.

Namespace:  Microsoft.AnalysisServices.AdomdServer
Assembly:  msmgdsrv (em msmgdsrv.dll)

Sintaxe

'Declaração
Public NotInheritable Class SafeToPrepareAttribute _
    Inherits Attribute
'Uso
Dim instance As SafeToPrepareAttribute

public sealed class SafeToPrepareAttribute : Attribute

public ref class SafeToPrepareAttribute sealed : public Attribute

[<SealedAttribute>]
type SafeToPrepareAttribute =  
    class
        inherit Attribute
    end

public final class SafeToPrepareAttribute extends Attribute

Comentários

If a user defined function (UDF) returns a DataTable, the UDF should be able to prepare for execution by running with the ExecuteForPrepare property set to true. To prepare for execution, the UDF should determine the structure of the DataTable needed to be returned, and return an empty DataTable that is structured appropriately.

Exemplos

In the following example, a simple UDF creates a DataTable. If the UDF runs with the ExecuteForPrepare property set to true, the UDF returns with an empty version of the DataTable. If the UDF runs with the ExecuteForPrepare property set to false, the UDF continues, populates the DataTable, and returns the populated DataTable.

[SafeToPrepare(true)]
public System.Data.DataTable GetPreparedTable()
{
    System.Data.DataTable results = new System.Data.DataTable();
    results.Columns.Add("A", typeof(int));
    results.Columns.Add("B", typeof(string));

    if (Context.ExecuteForPrepare)
    {
        // If preparing, return just the schema with no data
        return results;
    }

    //Otherwise return data
    object[] row = new object[2];
    row[0] = 1;
    row[1] = "A";
    results.Rows.Add(row);

    row[0] = 2;
    row[1] = "B";
    results.Rows.Add(row);

    return results;
}

Hierarquia de herança

System. . :: . .Object
  System. . :: . .Attribute
    Microsoft.AnalysisServices.AdomdServer..::..SafeToPrepareAttribute

Segurança de thread

Quaisquer membros static (Shared no Visual Basic) públicos deste tipo são thread-safe. Não há garantia de que qualquer membro de instância seja thread-safe.