RemoveLink(ProviderField: String; ConsumerField: String);
ProviderField. Data provider field identifier.
ConsumerField. Data consumer field identifier.
NOTE. Parameters values are case-sensitive. Fields identifiers must be set in upper case.
The RemoveLink method removes the link between the specified data source and data consumer fields.
The example displays copying data from a text file to a repository table. Executing the example requires that the repository contains an ETL task with the OBJ_ETL identifier and a table with the OBJ_TBL identifier. The file system must also contain the text file C:\ETL_imp.txt.
The first four lines of a text file used in the example:
"Key","Country Name","Owner"
512,"Afghanistan",3
914,"Albania",1
612,"Algeria",
Fields of the table used in the example:
KEY. Field with integer type.
COUNTRY_NAME. Field with string type.
OWNER. Field with string type.
Sub UserProc;
Var
Mb: IMetabase;
Task: IEtlTask;
CopyObj: IEtlPlainDataCopy;
FProvider: IDtTextProvider;
Tab: IDatasetModel;
FConsumer: IDtMetabaseConsumer;
ProvFields, ConsFields: IDtFieldDefinitions;
i: Integer;
WxConsumer: IWxRectangle;
WxETLConsumer: IWxEtlObject;
Begin
Mb := MetabaseClass.Active;
Task := MB.ItemById("OBJ_ETL").Edit As IEtlTask;
// Create an object that copies data
CopyObj := Task.Create(EtlObjectType.PlainDataCopy) As IEtlPlainDataCopy;
CopyObj := CopyObj.Edit;
// Set up data source parameters
FProvider := New DtTextProvider.Create As IDtTextProvider;
FProvider.File := "C:\ETL_imp.txt";
FProvider.DelimitedColumnDelimiter := ",";
FProvider.HeaderRow := 1;
FProvider.FormatType := DtTextFormatType.Delimited;
FProvider.RangeHasHeader := True;
FProvider.RangeFirstRow := 1;
COpyObj.Provider := FProvider;
// Set up data consumer parameters
FConsumer := New DtMetabaseConsumer.Create;
Tab := MB.ItemById("OBJ_TBL").Edit As IDatasetModel;
FConsumer.Dataset := Tab;
CopyObj.Consumer := FConsumer;
// Link source and consumer data
ProvFields := FProvider.Fields;
ConsFields := FConsumer.Fields;
CopyObj.AutoLink;
For i := 0 To ProvFields.Count - 1 Do
If Not CopyObj.IsLinked(ProvFields.Item(i).Name, ConsFields.Item(i).Name) Then
CopyObj.AddLink(ProvFields.Item(i).Name, ConsFields.Item(i).Name);
End If;
End For;
//Unbind by the "OWNER" field
CopyObj.RemoveLink("OWNER", "OWNER");
// Clear data consumer
CopyObj.ClearConsumer := True;
//Handle errors
CopyObj.ActionOnProblem := EtlActionOnProblem.DiscardRecordsInTransaction;
CopyObj.CommitCount := 10;
// Save the object that copies data
CopyObj.Save;
//Start of visual object creation
WxConsumer := Task.Workspace.CreateRectangle;
WxETLConsumer := New WxEtlObject.Create;
WxETLConsumer.EtlObject := CopyObj;
WxConsumer.Style.TextPosition := WxTextPosition.Bottom;
WxConsumer.Style.PictureMarginTop := -10;
WxConsumer.PinPosition := New GxPointF.Create(50, 50);
WxConsumer.Extension := WxETLConsumer As IWxShapeExtension;
//End of visual object creation
//Execute task
Task.Execute(Null);
//Save ETL task object
(Task As IMetabaseObject).Save;
End Sub UserProc;
After executing the example a new object that copies data is created in ETL task. Copying is performed from a text file into a repository table. Fields of data provider and data consumer are bound automatically. If any link between fields of data source and data consumer cannot be created automatically, it can be added manually. The link by the OWNER field is removed. Thus, copying is performed only by the KEY and COUNTRY_NAME fields. If errors occur on loading, records within one transaction will be ignored. 10 records are processed within one transaction. After the copied object is saved, ETL task will be run for execution.
See also: