Using a Data Source allows you to create a virtual view that is made and stored in the server without modifying the original data source. Databases typically contain data in tables that are optimized for storage and retrieval. In order to be rendered for presentation, columns with data relevant to users need to be joined across several tables, filtered by business needs, secured against unauthorized access, and labelled using user-friendly names. In relational databases, a view can perform some of these functions. In the server, a Data Source performs all of these functions, and more (such as the localization of report text and permissions based on data values).
Through a Data Source, users see columns that have been joined, filtered, and labelled for their specific business needs. Security policies limit the data values accessible by users through a Data Source. Administrators with organizational privileges define Data Sources for users to create reports using the Ad Hoc Editor.
Data Sources (and Topics) are used in the Zoola™ Ad Hoc Editor as a basis for designing reports. Users can save a report based on a Data Source for others to run, and can also save the settings in a Data Source Topic so that others can design similar reports.
Using a Data Source instead of a Topic has the following advantages:
Data Sources can be created directly through the user interface.
Data Source creators can write SQL queries, joins, filter expressions, and security files to specify exactly what data can be accessed, as well as labels and locale bundles to specify how the data appears.
A Data Source design typically includes data filtering, but users who create Reports using the Data Source can filter data even further. Users can select a subset of columns to appear in the Ad Hoc Editor and give them custom labels. Users can filter the data for each column.
Users creating Reports can design prompts for input from Report readers to filter data that appears in the document.
The following video walkthrough offers an overview of designing Data Sources in Zoola™: