--- title: "Transform data between tables with the Aggregate action" description: "This article is about actions that use Data Platform's proprietary Python data processing engine" url: https://docs.ovhcloud.com/pl/guides/public-cloud/data-platform/dpe-actions-aggregate lang: pl lastUpdated: 2026-09-14 --- > For AI agents: the complete documentation index is available at https://docs.ovhcloud.com/pl/llms.txt, the full documentation bundle is available at https://docs.ovhcloud.com/pl/llms-full.txt. # Transform data between tables with the Aggregate action ## Objective :::info This article is about actions that use Data Platform's proprietary Python data processing engine. To use Apache Spark clusters, see [Aggregate PySpark action](https://docs.ovhcloud.com/pl/guides/public-cloud/data-platform/dpe-actions-aggregate-pyspark.md). ::: The _Aggregate_ action allows you to transfer data from any pre-existing table into any other table, including the same table. The Aggregate action's scope - which typically allows SQL handling as well as joining multiple tables and grouping results - is wide, making it one of the most used action in data processing workflows. ## Configure an Aggregate action An Aggregate action is composed of a list of one or more _source tables_ from which the values will be extracted and placed into a single _destination table_. Each destination attribute needs to be mapped to a source attribute. When multiple _source tables_ are selected, it is necessary to specify a join condition, just like it's done in SQL. :::warning Note that leaving a destination attribute unmapped in the Aggregate action configuration **will trigger an error** when the action is launched. If you'd rather leave the destination field empty, make sure to simply remove it from the list of mapped attributes. ::: When destination attributes are removed from the list of mapped attributes, the following behavior shall be expected: - If the Aggregate action is **inserting new rows, it will simply fill the destination attribute column with NULL values**. - If the Aggregate action is **updating existing rows (i.e. inserting over existing data), it will leave the previous value intact regardless of whether it was NULL or not**. Use case examples for both single and multiple _source tables_ are described below. ### Transfer raw data into a primary table Create a new Aggregate action: ![Transfer raw data into a primary table — Agg ui](/images/public-cloud/data-platform/product/dpe/actions/aggregate/picts/agg-ui.png) Select the source (left) and destination table. Matching attributes are automatically assigned where possible. It is possible to manually select which attributes are mapped between the source and destination. ![Transfer raw data into a primary table — Agg ui2](/images/public-cloud/data-platform/product/dpe/actions/aggregate/picts/agg-ui2.png) If needed, you can change the mapping to either SQL or plain text by clicking on the **MAP** button and selecting either _SQL_ or _txt_. In the attributes section, it is also possible to change the compute mode of each attribute. In the example above, _SELECT_ has been chosen but other options are available. Press _Create_ at the top right to create the action. ### Join a referential to a primary table To specify a join, click on **Add a source** located just below the source table, you will be prompted to select a table to join with. Select the type of join from the dropdown menu, and input the join conditions in the UI. Multiple source tables can be joined. ![Join a referential to a primary table — Agg ui3](/images/public-cloud/data-platform/product/dpe/actions/aggregate/picts/agg-ui3.png) Attributes from all the joined tables can then be selected in the bottom attributes section either from the dropdown menus or using SQL. ### Configure the action's preferences Once you're satisfied with the mapping of your attributes, use the [preferences tab to configure the action settings](https://docs.ovhcloud.com/pl/guides/public-cloud/data-platform/dpe-jobs-preferences.md). ![Configure the action's preferences — Load settings](/images/public-cloud/data-platform/product/dpe/actions/aggregate/picts/load-settings.png) ## Use the Advanced Mode If you need to access the JSON configuration file of the action, you can activate the Advanced mode by clicking on **Advanced** at the top of the page. [Use the Advanced mode of an Aggregate action](https://docs.ovhcloud.com/pl/guides/public-cloud/data-platform/dpe-actions-aggregate-advanced-mode.md) ## Go further If you need training or technical assistance to implement our solutions, contact your sales representative or click on [this link](https://www.ovhcloud.com/pl/professional-services/) to get a quote and ask our Professional Services experts for a custom analysis of your project. Ask questions, give your feedback and interact directly with the team building the Data Platform on the dedicated [Discord channel](https://discord.gg/ovhcloud). If you need support with your OVHcloud services, create a request in our [Help Centre](https://help.ovhcloud.com/csm?id=csm_get_help). Join our [community of users](https://community.ovhcloud.com/).