Rank transformation in mapping data flow

APPLIES TO: Azure Data Factory Azure Synapse Analytics

Data flows are available both in Azure Data Factory and Azure Synapse Pipelines. This article applies to mapping data flows. If you are new to transformations, please refer to the introductory article Transform data using a mapping data flow.

Use the rank transformation to generate an ordered ranking based upon sort conditions specified by the user.

Configuration

Rank settings

Case insensitive: If a sort column is of type string, case will be factored into the ranking.

Dense: If enabled, the rank column will be dense ranked. Each rank count will be a consecutive number and rank values won't be skipped after a tie.

Rank column: The name of the rank column generated. This column will be of type long.

Sort conditions: Choose which columns you're sorting by and in which order the sort happens. The order determines sorting priority.

The above configuration takes incoming basketball data and creates a rank column called 'pointsRanking'. The row with the highest value of the column PTS will have a pointsRanking value of 1.

Data flow script

Syntax

<incomingStream>
    rank(
        desc(<sortColumn1>),
        asc(<sortColumn2>),
        ...,
        caseInsensitive: { true | false }
        dense: { true | false }
        output(<rankColumn> as long)
    ) ~> <sortTransformationName<>

Example

Rank settings

The data flow script for the above rank configuration is in the following code snippet.

PruneColumns
    rank(
        desc(PTS, true),
        caseInsensitive: false,
        output(pointsRanking as long),
        dense: false
    ) ~> RankByPoints

Next steps

Filter rows based upon the rank values using the filter transformation.