Practical SQL Handbook, The: Using SQL Variants, Fourth Edition

Avoiding Mistakes

SQL is an unusual computer language: It's not just for experts. There are still relatively few SQL mavens. Many users, in fact, are really C programmers or accountants or technical marketing whizzes. They pick up SQL on their own and learn by doing. They develop some skill but remain only occasional users. When they hit a snag, they don't have the luxury of appealing to a nearby guru.

Let's face it: SQL can be confusing. The code samples that follow are based on real-life problems submitted via the Internet, transposed to work on the now-familiar bookbiz database. In this case, though, they aren't examples to model or copy—they are illustrations of common misuses and misunderstandings.

This section doesn't contain complete explanations ...