Class RowComparer<T>

Creates a Comparison<T> (available in Comparison) and a Comparer<T> (available in Comparer) for comparing two rows of the same type, using high performance generated code.

Use RowComparer<TLeft, TRight> instead if either the rows have different types, or they are the same type and you also need to compare different columns (e.g. column "A" in one row with column "B" in the other row, even though the rows are the same type).

Also see Compare Dataflow Columns.

Inheritance

Object

RowComparer<T>

Implements

IRowComparerCommand<T>

IFluentInterface

Namespace: actionETL

Assembly: actionETL.dll

Syntax

public sealed class RowComparer<T> : IRowComparerCommand<T>, IFluentInterface where T : class

Type Parameters

Name	Description
T	The type of the rows.

Constructors

RowComparer(Action<IRowComparerCommand<T>>)

Initializes a new instance of the RowComparer<T> class with a row comparer command action, which specifies how to compare two rows of the same type. On return, Comparison will hold the generated row comparer, or null if a comparison could not be created. Comparer will hold the generated comparer, or will throw on access if it could not be created.

Also see Compare Dataflow Columns.

Declaration

public RowComparer(Action<IRowComparerCommand<T>> rowComparerCommandAction)

Parameters

Type	Name	Description
Action<IRowComparerCommand<T>>	rowComparerCommandAction	The row comparer command action, which specifies which columns to include in the comparison. Column name matching is ordinal case insensitive, but a case sensitive match takes precedence over a case insensitive match.

Exceptions

Type	Condition
ArgumentNullException	rowComparerCommandAction

Properties

Comparer

Gets the comparer that compares two rows, or throws if it could not be created.

Declaration

public Comparer<T> Comparer { get; }

Property Value

Type	Description
Comparer<T>

Exceptions

Type	Condition
InvalidOperationException	Could not create comparer.

Comparison

Gets the comparison that compares two rows, or null if it could not be created.

Declaration

public Comparison<T> Comparison { get; }

Property Value

Type	Description
Comparison<T>

Methods

ToString()

Returns a String that represents this instance.

Declaration

public override string ToString()

Returns

Type	Description
String

Overrides

Object.ToString()

Explicit Interface Implementations

IRowComparerCommand<T>.Asc(String)

Includes the specified column in the comparison, with values evaluated in ascending order.

Declaration

IRowComparerCommand<T> IRowComparerCommand<T>.Asc(string columnName)

Parameters

Type	Name	Description
String	columnName	Name of the column. Column name matching is ordinal case insensitive, but a case sensitive match takes precedence over a case insensitive match.

Returns

Type	Description
IRowComparerCommand<T>	The instance itself, for chaining multiple commands together.

Exceptions

Type	Condition
ArgumentException	Column cannot be null or whitespace. No matching column found.
InvalidOperationException	Found more than one member match in type. No .NET CLR Type information available. RowComparer: column type has no CompareTo() method.

IRowComparerCommand<T>.Asc(String, StringComparer)

Includes the specified column in the comparison, with values evaluated in ascending order.

Declaration

IRowComparerCommand<T> IRowComparerCommand<T>.Asc(string columnName, StringComparer stringComparer)

Parameters

Type	Name	Description
String	columnName	Name of the column. Column name matching is ordinal case insensitive, but a case sensitive match takes precedence over a case insensitive match.
StringComparer	stringComparer	The string comparer.

Returns

Type	Description
IRowComparerCommand<T>	The instance itself, for chaining multiple commands together.

Exceptions

Type	Condition
ArgumentException	Column cannot be null or whitespace. No matching column found.
ArgumentNullException	stringComparer
InvalidOperationException	Found more than one member match in type. No v CLR Type information available.

IRowComparerCommand<T>.Asc<TColumn>(String, Comparison<TColumn>)

Includes the specified column in the comparison, with values evaluated in ascending order.

Declaration

IRowComparerCommand<T> IRowComparerCommand<T>.Asc<TColumn>(string columnName, Comparison<TColumn> columnComparison)

Parameters

Type	Name	Description
String	columnName	Name of the column. Column name matching is ordinal case insensitive, but a case sensitive match takes precedence over a case insensitive match.
Comparison<TColumn>	columnComparison	The column comparison.

Returns

Type	Description
IRowComparerCommand<T>	The instance itself, for chaining multiple commands together.

Type Parameters

Name	Description
TColumn	The type of the column.

Exceptions

Type	Condition
ArgumentException	Column cannot be null or whitespace. No matching column found.
ArgumentNullException	columnComparison
InvalidOperationException	Found more than one member match in type. No .NET CLR Type information available.

IRowComparerCommand<T>.Desc(String)

Includes the specified column in the comparison, with values evaluated in descending order.

Declaration

IRowComparerCommand<T> IRowComparerCommand<T>.Desc(string columnName)

Parameters

Type	Name	Description
String	columnName	Name of the column. Column name matching is ordinal case insensitive, but a case sensitive match takes precedence over a case insensitive match.

Returns

Type	Description
IRowComparerCommand<T>	The instance itself, for chaining multiple commands together.

Exceptions

Type	Condition
ArgumentException	Column cannot be null or whitespace. No matching column found.
InvalidOperationException	Found more than one member match in type. No .NET CLR Type information available. RowComparer: column type has no CompareTo() method.

IRowComparerCommand<T>.Desc(String, StringComparer)

Includes the specified column in the comparison, with values evaluated in descending order.

Declaration

IRowComparerCommand<T> IRowComparerCommand<T>.Desc(string columnName, StringComparer stringComparer)

Parameters

Type	Name	Description
String	columnName	Name of the column. Column name matching is ordinal case insensitive, but a case sensitive match takes precedence over a case insensitive match.
StringComparer	stringComparer	The string comparer.

Returns

Type	Description
IRowComparerCommand<T>	The instance itself, for chaining multiple commands together.

Exceptions

Type	Condition
ArgumentException	Column cannot be null or whitespace. No matching column found.
ArgumentNullException	stringComparer
InvalidOperationException	Found more than one member match in type. No .NET CLR Type information available.

IRowComparerCommand<T>.Desc<TColumn>(String, Comparison<TColumn>)

Includes the specified column in the comparison, with values evaluated in descending order.

Declaration

IRowComparerCommand<T> IRowComparerCommand<T>.Desc<TColumn>(string columnName, Comparison<TColumn> columnComparison)

Parameters

Type	Name	Description
String	columnName	Name of the column. Column name matching is ordinal case insensitive, but a case sensitive match takes precedence over a case insensitive match.
Comparison<TColumn>	columnComparison	The column comparison.

Returns

Type	Description
IRowComparerCommand<T>	The instance itself, for chaining multiple commands together.

Type Parameters

Name	Description
TColumn	The type of the column.

Exceptions

Type	Condition
ArgumentException	Column cannot be null or whitespace. No matching column found.
ArgumentNullException	columnComparison
InvalidOperationException	Found more than one member match in type. No .NET CLR Type information available.

Implements

IRowComparerCommand<T>

IFluentInterface