Beginning_SQL_Queries

说明：   The syntax of SQL is quite easy to learn. A few basic ideas and a handful of keywords allow you to tackle a huge range of queries. However, many users often find themselves completely stumped when faced with a particular problem. It isn’t really a great deal of help for someone to say “this is how I would do it.” What you need is a variety of ways to get started on a tricky problem. Once you have made a start on a query, you need to be able to check, amend, and refine your solution until you have what you need.