Grouping.By Method

public static GroupingTemplate<TKey> By<TKey, C>(
	C columnKey
)

Public Shared Function By(Of TKey, C) ( 
	columnKey As C
) As GroupingTemplate(Of TKey)

public:
generic<typename TKey, typename C>
static GroupingTemplate<TKey>^ By(
	C columnKey
)

static member By : 
        columnKey : 'C -> GroupingTemplate<'TKey> 

Parameters

columnKey  C

The key of the grouping column.

Type Parameters

TKey

The type of the group keys produced when the template is bound.

C

The type of the dataframe column key.

Return Value

This overload creates a key-based column selector and does not bind immediately. Missing-column and key-type mismatch errors are reported when the template is bound.

public static GroupingTemplate<TKey> By<TKey>(
	ColumnSelector selector
)

Public Shared Function By(Of TKey) ( 
	selector As ColumnSelector
) As GroupingTemplate(Of TKey)

public:
generic<typename TKey>
static GroupingTemplate<TKey>^ By(
	ColumnSelector^ selector
)

static member By : 
        selector : ColumnSelector -> GroupingTemplate<'TKey> 

Parameters

selector  ColumnSelector

A selector that must resolve to exactly one dataframe column.

Type Parameters

TKey

The type of the group keys produced when the template is bound.

Return Value

The factory does not inspect or bind to a data frame. The selector is resolved when Bind(IDataFrame) is called. Binding normalizes the selected column through the existing categorical-vector mechanism and returns a realized Grouping<TKey>.

The selector must resolve to exactly one column when the template is bound. Missing explicit keys and selector key-type mismatches use the normal selector resolution behavior.

This first implementation supports single-column dataframe grouping templates only.

Reference