Basic Concepts when Working with Tables
The Table is a powerful report item that enables you to display detail and grouped data. The Table retrieves the detail report data from the data source and also allows you to organize aggregated detail data into groups.
The Table report item supports the Table, CrossTab, and List template variations, which are actually optimized alternatives of the same concept for a specific data layout. By default, a Table item displays detail data in a grid layout, a CrossTab displays grouped data in a grid layout, and a List displays detail data in a free-form layout.
By design, each Table or CrossTab cell contains a text box. You can add multiple report items to a Table cell by first adding a Panel item as a container and, then, the report items to the Panel. Each List cell contains a Panel. You can replace a default report item with another report item, for example, an image.
As you define groups for a Table, CrossTab, or List, the Report Designer adds rows and columns to the Table in which to display grouped data.
Detail vs. Grouped Data
Detail data is all the data that comes back from the table data source. Detail data is essentially what you see in the query designer results pane when you run a database query.
The actual detail data includes, and is restricted by, filters that are set on the data source, data region, and details group. To display detail data on a detail row, use a simple expression such as =Fields.ProductCategory. When the report runs, the detail row repeats once for each row in the query results at runtime.
Grouped data is detail data that is organized by a value that you specify in the group definition, for example, =Fields.ProductCategory. To display grouped data in group rows and columns, use a simple expressions that aggregates the grouped data such as =Sum(Fields.Quantity). The result will be the sum of all quantity values with the same product category as the current group.
Group Hierarchies
Groups are organized as members of group hierarchies. Row group and column group hierarchies are identical structures on different axes. Think of row groups as expanding down the page and column groups as expanding across the page.
A tree structure represents nested row and column groups that have a parent/child relationship, for example, a category with sub categories. The parent group is the root of the tree and child groups are its branches. Groups can also have an independent, adjacent relationship, for example, sales by territory and sales by year. Multiple unrelated tree hierarchies are called a forest. In a Table, row groups and columns groups are each represented as an independent forest.
The Table Item
A Table consists of the following areas:
- (Mandatory) Table Body—The Table Body area always exists. Its cells display detail and group data.
- (Optional) Corner—The cells in the Table Corner area are created automatically when you define both the row and column groups. For more information, refer to the article on Table Areas.
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(Optional) Row Group—The cells in the Row Group area are created automatically when you create a row group. These are row group header cells and display row group instance values by default.
For example, when you group by
=Fields.ProductCategory, group instance values are the individual product categories by which you are grouping the data. -
(Optional) Column Group—The cells in the Column Group area are created automatically when you create a column group. These are column group header cells and display column group instance values by default.
For example, when you group by
=Fields.Year, group instance values are the individual years by which you are grouping the data.
Static and Dynamic Rows and Columns
A Table item organizes cells in rows and columns that are associated with groups. Because group structures for row and column groups are identical, the documentation refers to them as row groups and you can apply the same concepts to column groups.
A row is either static or dynamic. A static row is not associated to a group. When the report runs, a static row renders once. Table headers and footers are static rows. Static rows should display labels and aggregates. If you don't specify an aggregate function in an Expression in a static row cell, the Table will use the First function by default.
A dynamic row is associated to one or more groups. A dynamic row renders once for every unique group value for the innermost group. Cells in a dynamic row are scoped to the innermost row and column group to which the cell belongs.
Dynamic detail rows are associated with the details group that is automatically created when you add a table or list to the design surface. By definition, the details group is the innermost group for a table. Cells in detail rows display detail data.