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Adding Unions/Joins/ Projections/ Aggregation
a. From the Tools Palette, choose the required option as follows:
View Description
Union Used to combine the result set of two or more data
sources. For example, to show the names of all the
employees of a store which has different branches each
maintaining its own employee records table.
Join Used to query data from two or more data sources,
based on a specified condition. For example, to retrieve
the sales of two stores maintaining individual table for
sales based on the customer ID.
Projection Used to filter or create a subset of the required columns
of a table or view for creating the model. For example,
selecting the employee name and sales quantity from a
table consisting of many more columns.
Aggregation Used to summarize data of a group of rows by
calculating values in a column. For example, to retrieve
total sales of a product in a month. The supported
aggregation types are sum, min, and max.
Note:
○ The input for union, join, projection, and aggregation views can consist of data sources, union,
join, projection, or aggregation views.
○ You can have only one source of input for aggregation and projection views.
○ You can choose to create filters on projection and aggregation view attributes.
b. Map the input to the selected option.
Mapping attributes
a. To map attributes in a union view, drag and drop the required columns from Source to Target.
You can also modify the attribute mapping. For more information, see Managing Attribute Mappings
[page 122]
Tip: To create a system generated mapping, choose Auto Map By Name.
b. In case of a join view, join the columns of the source data sources.
Note:
○ The output of a union view is the attributes that you added to the Target.
○ The output of a join view is the joined attributes. However, to add additional attributes to the
view's output, from the context menu, choose Add to Output.
○ To add attributes of projection or aggregation view to its output, choose Add to Output from
the context menu.
P U B L I C
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SAP HANA Developer Guide
Setting Up the Analytic Model