We've already seen that Tableau can connect to nearly any data source. Whether it's a built-in direct connection or ODBC or whether it's using the Tableau Data Extract API to generate an extract, no data is off-limits. However, there are certain structures that make data easier to work with in Tableau.
There are two key ways to ensure a good data structure that works well with Tableau:
Every record of a source data connection should be at a meaningful level of detail
Every measure contained in the source should match the level of detail or possibly be at a higher level of detail; however, it should never be at a lower level of detail
For example, you may have one record per class in a school. Within the record, you may have three measures: the average GPA of the class, the number of students in the class, and the average GPA of the school. The first two measures are at the same level of detail as the individual record of data (per student). The GPA for the school...