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Row Duplication

The RowDuplication transformation is used to create duplicates of incoming rows in your data flow. It allows you to define how many copies of a row should be made and provides an optional predicate to control which rows are duplicated.

Buffering Behavior

  • Non-blocking transformation
  • One input buffer
  • Output includes the original row plus duplicates

By default, cloning uses a specialized mechanism that copies all public properties and fields. Non-public members are not included. For custom cloning logic, implement ICloneable or use the CustomCloningStrategy property.

Basic Usage

You can create a RowDuplication and specify the number of duplicates either via the constructor or the NumberOfDuplicates property.

var source = new DbSource<InputType>("SourceTable");
var duplication = new RowDuplication<InputType>(3);
var dest = new CsvDestination<InputType>("output.csv");

source.LinkTo(duplication).LinkTo(dest);

This creates 3 duplicates of every row, resulting in 4 total outputs per input row (original + 3 copies).

Example: Duplicate All Rows

public class MyRow {
    public string Value { get; set; }
}

public static void Main() {
    var source = new MemorySource<MyRow>();
    source.DataAsList.Add(new MyRow() { Value = "A" });
    source.DataAsList.Add(new MyRow() { Value = "B" });

    var duplication = new RowDuplication<MyRow>();
    duplication.NumberOfDuplicates = 2;

    var dest = new MemoryDestination<MyRow>();

    source.LinkTo(duplication).LinkTo(dest);
    Network.Execute(source);

    foreach (var row in dest.Data)
        Console.WriteLine($"Value:{row.Value}");

    // Output:
    // Value:A
    // Value:A
    // Value:A
    // Value:B
    // Value:B
    // Value:B
}

The default NumberOfDuplicates is 1, meaning the original row plus one copy (total of two).

Conditional Duplication with Predicate

You can control which rows are duplicated using the CanDuplicate predicate. If this predicate evaluates to false, no duplicates are created (only the original row is passed through).

Example: Duplicate Only Selected Rows

var duplication = new RowDuplication<MyRow>();
duplication.NumberOfDuplicates = 2;
duplication.CanDuplicate = row => row.Value == "A";

This will result in:

Value:A
Value:A
Value:A
Value:B

Dynamic Object Support

The RowDuplication transformation also supports ExpandoObject. This allows working with dynamic data where schema is not fixed at compile time.

var source = new MemorySource();
dynamic r1 = new ExpandoObject();
r1.Value = "X";
source.DataAsList.Add(r1);

var duplication = new RowDuplication();
duplication.NumberOfDuplicates = 2;

var dest = new MemoryDestination();

source.LinkTo(duplication).LinkTo(dest);
Network.Execute(source);

// Output will include the original plus two duplicates of the dynamic object
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