One of the most important features released in 2017 was the ability to use published Power BI datasets as a source for Power BI reports. With Live connections to Power BI datasets, report authors can develop reports in Power BI Desktop files containing only the visualization layer (for example, report pages of visuals) while leveraging a single dataset.

The dataset, which is generally developed and managed by a different user or team, already includes the data retrieval supporting tables and columns, the data model relationships, and the DAX measures or calculations as described in previous chapters. Once the Live connection report is developed and published to Power BI, it will maintain its connection to the source dataset and will be refreshed with the refresh schedule configured for the dataset.

Prior to Live connection reports to Power BI datasets, users within teams would frequently create multiple versions of the same dataset in order to create different reports. As both a report and a dataset, each individual report would require its own scheduled refresh process (in import mode), its own data storage, and would create version control problems as the report author could modify the underlying dataset. Live connection reports therefore severely reduce resource requirements and promote a single version of the truth. Moreover, Live connection reports facilitate the isolation of report design and development from dataset design and development.

Most Power BI report authors will not be interested in or responsible for dataset design topics, such as data retrieval with M queries, data modeling, and DAX measures. Likewise, a dataset designer is often less interested in or responsible for visualization best practices and the engagement with the actual users of reports and dashboards. As advised in Chapter 7, Planning Power BI Projects, it's important for the alternative roles (dataset designer, report author) to regularly collaborate, such as by identifying measures or columns that need to be added to the dataset to support reports and dashboards.

To create a Live connection report with a published Power BI dataset as the source, the report author needs a Power BI Pro license and will need to be a member of the app workspace hosting the dataset with edit rights.

In the following example, the report author is a member of the Corporate Sales app workspace and creates a new report in Power BI Desktop by connecting to the AdWorks Enterprise dataset within this workspace:

Creating a Live connection to the Power BI dataset

After selecting the Power BI service from the list of Online Services within the Get Data dialog, the list of the workspaces of which the report author is a member is prompted. In this example, either double-clicking the AdWorks Enterprise dataset or clicking the Load button will establish the Live connection per the status bar in Power BI Desktop:

Live connection status bar

The same field list of measures and tables is exposed in Report View but the Relationship View and Data View do not appear. Likewise, once the Live connection has been established, the Get Data dialog is also grayed out. Live connection reports to Power BI datasets and SQL Server Analysis Services (SSAS) databases are always limited to a single data model as a source.

Live connection reports are published to the same app workspace as their source dataset. In the following example, a report file named USA Sales and Margin, which is connected to the AdWorks Enterprise dataset in the Corporate Sales workspace has been published from Power BI Desktop:

Published Live connection report

Per the preceding image, the report will appear in the workspace of the source dataset (Corporate Sales) in Power BI. Since the report was published from Power BI Desktop, the report (.pbix file) can be downloaded by opening the report and clicking Download report from the File menu.

It's possible to create reports based on Power BI datasets within the Power BI online service. However, the .pbix files for these reports cannot be downloaded and thus all edits must be implemented within the service without version history. Additionally, several important report authoring features in Power BI Desktop are not supported in the service, including the alignment of objects and local report measures. Given these considerations, Power BI Desktop is recommended for any report development beyond personal or ad hoc use. Guidance on version history for Power BI Desktop files (reports and datasets) is included in Chapter 14, Managing Application Workspaces and Content.