Report Datasets (Report Designer)
The Report Datasets window is used in the Data and Layout views of a report. Use the Report Datasets window to view all of the datasets that are defined for the current report. A dataset defines a connection to a data source and a query or stored procedure that retrieves data when the report is processed. A dataset is a representation of the actual data that appears in the report when you preview or run it.
Fields in a dataset that are bound to a data regions (such as a table, matrix, list, or chart) return multiple rows of data from the data source at processing time. If the dataset field is bound to a report item that is not a data region, only a single value is processed for the field.
To add a dataset to a report, from the Report menu, choose View, and then click Data. On the toolbar, click the down arrow to show the Dataset drop-down list, and choose <New Dataset>. In the Datasets window, you can expand a dataset node to view the fields defined for it. For more information, see How to: Refresh Fields in the Datasets Window (Report Designer).
To modify the collection of fields defined for a dataset, see How to: Add, Edit, or Delete a Field in the Datasets Window (Report Designer).
To use fields from a dataset in a report, from the Report menu, choose View, and then click Layout. From the toolbox, drag a data region (table, matrix, list, or chart) to the report design surface. From the View menu, click Datasets. You can expand each dataset node to view the defined fields. Drag a field onto a data region text box or other report item.
When you drag a field onto a data region, the default expression for that field appears (for example,
Fields!LastName.Value). When the report is processed, you see a value for each value returned from the data source for that field.
When you drag a field onto a report item other than a data region, the default expression indicates a single value for the field (for example,
First(Fields!LastName.Value). When the report is processed, you see the single value returned from the data source for that field.
For more information about using fields from an expression, see Using Global Collections in Expressions (Reporting Services).