ICubeMetaUpdateEx.ForceEmptyValues

Syntax

ForceEmptyValues: Boolean;

Description

The ForceEmptyValues property determines whether to replace the data points, that are missing in the source but present in the consumer, with empty values.

Comments

Available values:

True. Data points that are missing in the source but present in the consumer are replaced with Null.
False. Default value. Data points are not replaced.

Example

Executing the example requires that the repository contains a time series database with the TSDB identifier (data source) and a time series database with the TSDB_COPY identifier (data consumer). The time series databases must have matching structures.

Add links to the Cubes and Metabase system assemblies.

Sub UserProc;
Var
    Metabase: IMetabase;
    RubUpdateEx: ICubeMetaUpdateEx;
    Rub: IRubricator;
    Callback: MyUpdateCallback;
Begin
    // Get current time series database
    Metabase := MetabaseClass.Active;
    // Create an object for copying a time series database
    RubUpdateEx := New CubeMetaUpdateClass.Create As ICubeMetaUpdateEx;
    // Set copied time series database
    Rub := Metabase.ItemById("TSDB").Bind As IRubricator;
    RubUpdateEx.Rubricator := Rub;
    // Specify that data is copied with data and nested objects
    RubUpdateEx.CopyData := True;
    RubUpdateEx.CopyExtraObjects := False;
    // Specify repository and time series database, to which data is copied
    RubUpdateEx.Metabase := Metabase;
    RubUpdateEx.TargetRubricator := Metabase.ItemById("TSDB_COPY").Bind As IRubricator;
    // Specify that data points that are missing in the source, but present in the consumer,
    // are replaced with Null;
    RubUpdateEx.ForceEmptyValues := True;
    // Specify that data is copied within one transaction
    RubUpdateEx.DisableTransactions := True;
    // Specify that custom object is used for handling transactions
    Callback := New MyUpdateCallback.Create;
    RubUpdateEx.UpdateCallback := Callback;
    // Copy
    RubUpdateEx.Apply(Null);
End Sub UserProc;

// Class implementing events that occur in transactions during copying
Class MyUpdateCallback: CubeMetaUpdateCallback
    // Event that occurs on opening transaction and revision
    public Sub OnAfterStartTransaction(Rubricator: IRubricatorInstance; Connection: ISecurityConnection);
    Begin
        Debug.WriteLine("User " + Connection.UserNameLo + " has started copying");
    End Sub OnAfterStartTransaction;

    // Event that occurs before closing transaction and revision
    Public Sub OnBeforeCommit(Rubricator: IRubricatorInstance; Connection: ISecurityConnection);
    Begin
        Debug.WriteLine("User " + Connection.UserNameLo + " has finished copying");
    End Sub OnBeforeCommit;

End Class MyUpdateCallback;

After executing the example the TSDB time series database data is copied to the TSDB_COPY time series database within one transaction. Data points that are missing in the source but present in the consumer are replaced with Null. The console window displays information about start and finish of copying.