Class LookupTransformation<TInput, TSourceOutput>

The lookup transformation enriches the incoming data with data from the lookup source. Data from the lookup source is read into memory when the first record arrives. For each incoming row, the lookup tries to find a matching record in the memory table and uses this record to add additional data to the ingoing row.

Inheritance
System.Object
LoggableTask
DataFlowComponent
DataFlowSource<TInput>
DataFlowTransformation<TInput, TInput>
LookupTransformation<TInput, TSourceOutput>
LookupTransformation
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.ToString()
Namespace: ETLBox.DataFlow.Transformations
Assembly: ETLBox.dll
Syntax
public class LookupTransformation<TInput, TSourceOutput> : DataFlowTransformation<TInput, TInput>, ILoggableTask, IDataFlowLogging, IDataFlowTransformation<TInput, TInput>, IDataFlowSource<TInput>, IDataFlowSource, IDataFlowDestination<TInput>, IDataFlowDestination, IDataFlowComponent
Type Parameters
Name Description
TInput

Type of ingoing and outgoing data.
TSourceOutput

Type of data used in the lookup source.
Examples
public class Order
{    
    public int OrderNumber { get; set; }
    public int CustomerId { get; set; }
    public string CustomerName { get; set; }
}

public class Customer
{
    [RetrieveColumn(nameof(Order.CustomerId))]
    public int Id { get; set; }

    [MatchColumn(nameof(Order.CustomerName))]
    public string Name { get; set; }
}

DbSource<Order> orderSource = new DbSource<Order>("OrderData");
CsvSource<Customer> lookupSource = new CsvSource<Customer>("CustomerData.csv");
var lookup = new LookupTransformation<Order, Customer>();
lookup.Source = lookupSource;
DbDestination<Order> dest = new DbDestination<Order>("OrderWithCustomerTable");
source.LinkTo(lookup).LinkTo(dest);

Constructors

LookupTransformation()

Declaration
public LookupTransformation()

LookupTransformation(IDataFlowExecutableSource<TSourceOutput>)

Declaration
public LookupTransformation(IDataFlowExecutableSource<TSourceOutput> lookupSource)
Parameters
Type Name Description
IDataFlowExecutableSource<TSourceOutput> lookupSource

Sets the Source of the lookup.

LookupTransformation(IDataFlowExecutableSource<TSourceOutput>, Func<TInput, TInput>)

Declaration
public LookupTransformation(IDataFlowExecutableSource<TSourceOutput> lookupSource, Func<TInput, TInput> transformationFunc)
Parameters
Type Name Description
IDataFlowExecutableSource<TSourceOutput> lookupSource

Sets the Source of the lookup.
System.Func<TInput, TInput> transformationFunc

Sets the TransformationFunc

LookupTransformation(IDataFlowExecutableSource<TSourceOutput>, Func<TInput, TInput>, IList<TSourceOutput>)

Declaration
public LookupTransformation(IDataFlowExecutableSource<TSourceOutput> lookupSource, Func<TInput, TInput> transformationFunc, IList<TSourceOutput> lookupList)
Parameters
Type Name Description
IDataFlowExecutableSource<TSourceOutput> lookupSource

Sets the Source of the lookup.
System.Func<TInput, TInput> transformationFunc

Sets the TransformationFunc
System.Collections.Generic.IList<TSourceOutput> lookupList

Sets the list for the LookupData

Properties

LookupData

Holds the data read from the lookup source. This data is used to find data that is missing in the incoming rows.

Declaration
public IList<TSourceOutput> LookupData { get; set; }
Property Value
Type Description
System.Collections.Generic.IList<TSourceOutput>

Source

The source component from which the lookup data is retrieved. E.g. a DbSource or a MemorySource.

Declaration
public IDataFlowExecutableSource<TSourceOutput> Source { get; set; }
Property Value
Type Description
IDataFlowExecutableSource<TSourceOutput>

SourceBlock

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

Declaration
public override ISourceBlock<TInput> SourceBlock { get; }
Property Value
Type Description
System.Threading.Tasks.Dataflow.ISourceBlock<TInput>
Overrides
ETLBox.DataFlow.DataFlowSource<TInput>.SourceBlock

TargetBlock

TargetBlock from the underlying TPL.Dataflow which is used as input buffer for the component.

Declaration
public override ITargetBlock<TInput> TargetBlock { get; }
Property Value
Type Description
System.Threading.Tasks.Dataflow.ITargetBlock<TInput>
Overrides
ETLBox.DataFlow.DataFlowTransformation<TInput, TInput>.TargetBlock

TaskName

A name to identify the task or component. Every component or task comes with a default name that can be overwritten.

Declaration
public override string TaskName { get; set; }
Property Value
Type Description
System.String
Overrides

TransformationFunc

A transformation func that describes how the ingoing data can be enriched with the already pre-read data from the Source

Declaration
public Func<TInput, TInput> TransformationFunc { get; set; }
Property Value
Type Description
System.Func<TInput, TInput>

Methods

CleanUpOnFaulted(Exception)

Declaration
protected override void CleanUpOnFaulted(Exception e)
Parameters
Type Name Description
System.Exception e
Overrides

CleanUpOnSuccess()

Declaration
protected override void CleanUpOnSuccess()
Overrides

FindFirst<T>(IList<T>, Func<T, Boolean>)

Declaration
public static T FindFirst<T>(IList<T> source, Func<T, bool> condition)
Parameters
Type Name Description
System.Collections.Generic.IList<T> source
System.Func<T, System.Boolean> condition
Returns
Type Description
T
Type Parameters
Name Description
T

InternalInitBufferObjects()

Declaration
protected override void InternalInitBufferObjects()
Overrides

LinkErrorTo(IDataFlowDestination<ETLBoxError>)

Declaration
public IDataFlowSource<ETLBoxError> LinkErrorTo(IDataFlowDestination<ETLBoxError> target)
Parameters
Type Name Description
IDataFlowDestination<ETLBoxError> target
Returns
Type Description
IDataFlowSource<ETLBoxError>

Implements