QUESTION
What are the steps to create a Cognos report with a chart? For example, the chart should show by month the number of tasks and how many of them are completed and not completed.
ANSWER
First a query subject is required with 3 query items:
1 - The month, e.g. month ([|Tasks].[|Task].[|PlannedFinish])
2 - The completed field: [|Tasks].[|Task].[|Completed]
3 - A field 'one' with the constant value 1
Then create the chart as:
1 - Categories (X-Axis) = query item 'month'
2 - Series = query item 'Completed'
3 - Default measure (Y-Axis) = query item 'one'