SQL - Tables

The majority of the examples in this blog involve the use of two tables, EMP and DEPT. The EMP table is a simple 14-row table with only numeric, string, and date fields. The DEPT table is a simple four-row table with only numeric and string fields. These tables appear in many old database texts, and the many-to-one relationship between departments and employees is well understood.

While I'm on the topic of the example tables, I want to mention that all but a very few solutions in this blog run against these tables. Nowhere do I tweak my example data to set up a solution that you would be unlikely to have a chance of implementing in the real world, as some books do.

And while I'm on the topic of solutions, let me just mention that whenever possible I've tried to provide a generic solution that will run on all five RDBMSs covered in this blog. Often that's not possible. Even so, in many cases more than one vendor shares a solution. Because of their mutual support for window functions, for example, Oracle and DB2 often share solutions. Whenever solutions are shared, or at least are very similar, discussions are shared as well.

As an aside, some vendors allow partial SELECT statements. For example, you can have SELECT without a FROM clause. I don't particularly like this, thus I select against a support table, T1, with a single row, rather than using partial queries.

Any other tables are specific to particular recipes and chapters, and will be introduced in the text when appropriate.