Artikel
05/23/2011

SafeToPrepareAttribute Class

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

Inheritance Hierarchy

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

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

Syntax

'Declaration
Public NotInheritable Class SafeToPrepareAttribute _
    Inherits Attribute
'Usage
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

The SafeToPrepareAttribute type exposes the following members.

Constructors

	Name	Description
	SafeToPrepareAttribute	Initializes a new instance of the SafeToPrepareAttribute class.

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Properties

	Name	Description
	IsSafeToPrepare	Gets a value that indicates whether the associated method is safe to run with the ExecuteForPrepare property set to true.
	TypeId	(Inherited from Attribute.)

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Methods

	Name	Description
	{dtor}	Releases all resources used by the SafeToPrepareAttribute.
	Equals	(Inherited from Attribute.)
	Finalize	(Inherited from Object.)
	GetHashCode	(Inherited from Attribute.)
	GetType	(Inherited from Object.)
	IsDefaultAttribute	(Inherited from Attribute.)
	Match	(Inherited from Attribute.)
	MemberwiseClone	(Inherited from Object.)
	ToString	(Inherited from Object.)

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Explicit Interface Implementations

	Name	Description
	_Attribute.GetIDsOfNames	(Inherited from Attribute.)
	_Attribute.GetTypeInfo	(Inherited from Attribute.)
	_Attribute.GetTypeInfoCount	(Inherited from Attribute.)
	_Attribute.Invoke	(Inherited from Attribute.)

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Remarks

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.

Examples

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;
}

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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