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Chapter 9: Working with Multiple Tables
Overview
One of the jobs of the report designer is to understand the meaning of the stored data and its inherent relationships. People who design and build a database are generally a different set of people than those who ultimately need to retrieve data from it. Database designers and programmers focus on capturing the right information and creating a storage facility to efficiently hold it. Business people, on the other hand, focus on the intelligence and sleuthing needed at the other end of the process to retrieve and synthesize the data in order to answer business questions. Because the two groups inherently have different purposes, bridging the gap between understanding the storage and knowing how to use the data to answer questions can be frustrating.As a report designer, you play a powerful role sitting in between the two groups and providing a context for the data in order to transform it into information. This puts the responsibility of accurately representing the data on your shoulders. Nothing brings this to the forefront any clearer than the need to work with multiple tables in a way that generates correct information. To build a good report, it is an absolute requirement that you understand the data relationships behind the report and how they can safely and accurately be combined.Featured in this chapter:
Understanding essential database concepts
Working with multiple tables
Creating database schemas
Defining business rules
Using the Database Expert Links dialog
Understanding the types of links
Creating an inner join
Creating a left outer join
Creating a right outer join
Creating a full outer join
