# MergeJoin {{< rawhtml >}}

Class MergeJoin<TInput1, TInput2, TOutput>

Will join data from the two inputs into one output. Make sure both inputs are sorted or in the right order. Each row from the left join target will be merged with a row from the right join target. If the amount of ingoing data is unevenly distributed, the last rows will be joined with null values.

You can define a match condition that let you only merge matching records. This will change the match behavior a little bit. By assuming that the input is sorted, not matching records will be joined with null then. This can be compared with a left or right join.

Inheritance
object
LoggableTask
DataFlowComponent
DataFlowSource<TOutput>
MergeJoin<TInput1, TInput2, TOutput>
MergeJoin
MergeJoin
MergeJoin<TInput>
MergeJoin<TInput>
Implements
IDataFlowSource<TOutput>
IDataFlowSource
IDataFlowDestination
IDataFlowComponent
ILoggableTask
Inherited Members
DataFlowSource<TOutput>.LinkTo(IDataFlowDestination<TOutput>)
DataFlowSource<TOutput>.LinkTo(IDataFlowDestination<TOutput>, Predicate<TOutput>)
DataFlowSource<TOutput>.LinkTo(IDataFlowDestination<TOutput>, Predicate<TOutput>, Predicate<TOutput>)
DataFlowSource<TOutput>.LinkTo<TConvert>(IDataFlowDestination<TOutput>)
DataFlowSource<TOutput>.LinkTo<TConvert>(IDataFlowDestination<TOutput>, Predicate<TOutput>)
DataFlowSource<TOutput>.LinkTo<TConvert>(IDataFlowDestination<TOutput>, Predicate<TOutput>, Predicate<TOutput>)
DataFlowComponent.MaxBufferSize
DataFlowComponent.Predecessors
DataFlowComponent.Successors
DataFlowComponent.Completion
DataFlowComponent.BufferCancellationSource
DataFlowComponent.BufferCancellationToken
DataFlowComponent.WasComponentInitialized
DataFlowComponent.IsReadyForProcessing
DataFlowComponent.SetParentComponent(DataFlowComponent)
DataFlowComponent.LinkErrorTo(IDataFlowDestination<ETLBoxError>)
DataFlowComponent.InternalLinkTo<T>(IDataFlowDestination, object, object)
DataFlowComponent.AddComplementVoidLinkToOtherTargets(Func<Type, IDataFlowDestination>, Delegate)
DataFlowComponent.ResetComponent()
DataFlowComponent.InitBufferObjects(CancellationToken?)
DataFlowComponent.PrepareParameterForCheck()
DataFlowComponent.InitCheckedParameter()
DataFlowComponent.OnInitialization
DataFlowComponent.OnCompletion
DataFlowComponent.OnException
DataFlowComponent.CompleteOrFaultBufferOnPredecessorCompletion(Task)
DataFlowComponent.Exception
DataFlowComponent.ErrorSource
DataFlowComponent.CancelBufferAndThrowOperationCanceledException()
DataFlowComponent.InternalLinkErrorTo(IDataFlowDestination<ETLBoxError>)
DataFlowComponent.ThrowOrRedirectError(Exception, string, string)
DataFlowComponent.ThrowErrorAndFaultNetwork(Exception, string)
DataFlowComponent.CancelComponent()
DataFlowComponent.ErrorCount
DataFlowComponent.ProgressCount
DataFlowComponent.OnProgress
DataFlowComponent.ExecutionStartTime
DataFlowComponent.ExecutionEndTime
DataFlowComponent.Tag
DataFlowComponent.LoggingStartOnce()
DataFlowComponent.LoggingFinishOnce()
DataFlowComponent.LogProgressBatch_AfterThrowOrRedirectError(int)
DataFlowComponent.LogProgress_AfterThrowOrRedirectError()
LoggableTask.TaskType
LoggableTask.TaskName
LoggableTask.DisableLogging
LoggableTask.LogThreshold
LoggableTask.TaskHash
LoggableTask.LogInstance
LoggableTask.ParentTask
LoggableTask.LogTrace(string, params object[])
LoggableTask.LogDebug(string, params object[])
LoggableTask.LogInfo(string, params object[])
LoggableTask.LogInfoOrDebug(string, params object[])
LoggableTask.LogWarn(string, params object[])
LoggableTask.LogError(string, params object[])
LoggableTask.LogFatal(string, params object[])
object.Equals(object)
object.Equals(object, object)
object.GetHashCode()
object.GetType()
object.MemberwiseClone()
object.ReferenceEquals(object, object)
object.ToString()
Namespace: ETLBox.DataFlow
Assembly: ETLBox.dll
Syntax
{{< /rawhtml >}} ```C# public class MergeJoin : DataFlowSource, IDataFlowSource, IDataFlowSource, IDataFlowDestination, IDataFlowComponent, ILoggableTask ``` {{< rawhtml >}}
Type Parameters
Name Description
TInput1

Type of ingoing data for the left join target.
TInput2

Type of ingoing data for the right join target.
TOutput

Type of outgoing data.
Examples
MergeJoin<InputType1, InputType2, OutputType> join = new MergeJoin<InputType1, InputType2, OutputType>();
join.MergeJoinFunc =  (leftRow, rightRow) => {
    return new OutputType()
    {
        Result = leftRow.Value 1 + rightRow.Value2
    };
});
source1.LinkTo(join.LeftInput);
source2.LinkTo(join.RightInput);
join.LinkTo(dest);

Constructors

MergeJoin()

Declaration
{{< /rawhtml >}} ```C# public MergeJoin() ``` {{< rawhtml >}}

MergeJoin(Func<TInput1, TInput2, TOutput>)

Declaration
{{< /rawhtml >}} ```C# public MergeJoin(Func mergeJoinFunc) ``` {{< rawhtml >}}
Parameters
Type Name Description
Func<TInput1, TInput2, TOutput> mergeJoinFunc

Sets the MergeJoinFunc

MergeJoin(Func<TInput1, TInput2, TOutput>, Func<TInput1, TInput2, int>)

Declaration
{{< /rawhtml >}} ```C# public MergeJoin(Func mergeJoinFunc, Func comparisonFunc) ``` {{< rawhtml >}}
Parameters
Type Name Description
Func<TInput1, TInput2, TOutput> mergeJoinFunc

Sets the MergeJoinFunc
Func<TInput1, TInput2, int> comparisonFunc

Sets the ComparisonFunc

Properties

Buffer

Declaration
{{< /rawhtml >}} ```C# protected BufferBlock Buffer { get; set; } ``` {{< rawhtml >}}
Property Value
Type Description
BufferBlock<TOutput>

ComparisonFunc

If the ComparisonFunc is defined, records are compared regarding their sort order and only joined if they match. Return 0 if both records match and should be joined. Return a value little than 0 if the record of the left input is in the sort order before the record of the right input. Return a value greater than 0 if the record for the right input is in the order before the record from the left input.

Declaration
{{< /rawhtml >}} ```C# public Func ComparisonFunc { get; set; } ``` {{< rawhtml >}}
Property Value
Type Description
Func<TInput1, TInput2, int>
Remarks

Make sure that both inputs are sorted, and the comparison func take the sort order into account.

LeftInput

The left target of the merge join. Use this to link your source component with.

Declaration
{{< /rawhtml >}} ```C# public JoinTarget LeftInput { get; set; } ``` {{< rawhtml >}}
Property Value
Type Description
JoinTarget<TInput1>

MergeJoinFunc

The func that describes how both records from the left and right join target can be joined.

Declaration
{{< /rawhtml >}} ```C# public Func MergeJoinFunc { get; set; } ``` {{< rawhtml >}}
Property Value
Type Description
Func<TInput1, TInput2, TOutput>

RightInput

The right target of the merge join. Use this to link your source component with.

Declaration
{{< /rawhtml >}} ```C# public JoinTarget RightInput { get; set; } ``` {{< rawhtml >}}
Property Value
Type Description
JoinTarget<TInput2>

SourceBlock

SourceBlock from the underlying TPL.Dataflow which is used as output buffer for the component.

Declaration
{{< /rawhtml >}} ```C# public override ISourceBlock SourceBlock { get; } ``` {{< rawhtml >}}
Property Value
Type Description
ISourceBlock<TOutput>
Overrides

Methods

CheckParameter()

Declaration
{{< /rawhtml >}} ```C# protected override void CheckParameter() ``` {{< rawhtml >}}
Overrides

CleanUpOnFaulted(Exception)

Declaration
{{< /rawhtml >}} ```C# protected override void CleanUpOnFaulted(Exception e) ``` {{< rawhtml >}}
Parameters
Type Name Description
Exception e
Overrides

CleanUpOnSuccess()

Declaration
{{< /rawhtml >}} ```C# protected override void CleanUpOnSuccess() ``` {{< rawhtml >}}
Overrides

CompleteBuffer()

Declaration
{{< /rawhtml >}} ```C# protected override void CompleteBuffer() ``` {{< rawhtml >}}
Overrides

FaultBuffer(Exception)

Declaration
{{< /rawhtml >}} ```C# protected override void FaultBuffer(Exception e) ``` {{< rawhtml >}}
Parameters
Type Name Description
Exception e
Overrides

InitComponent()

Declaration
{{< /rawhtml >}} ```C# protected override void InitComponent() ``` {{< rawhtml >}}
Overrides

Reset()

Declaration
{{< /rawhtml >}} ```C# protected override void Reset() ``` {{< rawhtml >}}
Overrides

Implements

{{< /rawhtml >}}