Classe SafeToPrepareAttribute

Syntaxe

'Déclaration
Public NotInheritable Class SafeToPrepareAttribute _
    Inherits Attribute
'Utilisation
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

Notes

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.

Exemples

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;
}

Hiérarchie d'héritage

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

Sécurité des threads

Tous les membres publics static (Shared dans Visual Basic) de ce type sont thread-safe. Il n'est pas garanti que les membres d'instance soient thread-safe.

Voir aussi

Référence