The report dictionary contains a description of data in a structured view, for example in tables. Sometimes when creating reports you need to join data tables, sort, group, filter data, add some new elements, perform mathematical operations, and calculate the total for joined tables and much more.
You can transform data using different ways:
Write queries with parameters;
Change data structure in a storage;
Create a storage procedure and more.
However, you can use the Data Transformation tool in the report designer. Using this tool, you can create a description of data as a table. After that, you will be able to render some reports in the report designer based on this table.
To call the Data Transformation you should select the New Data Transformation command in the New Item menu of the data dictionary.
After you select this command, the New Data Transformation window will be called where you can transform data.