Q&A
How does all this information apply to me if I am not using SQL from the command line as depicted in the examples?
Whether you use SQL in COBOL as Embedded SQL or in Microsoft's Open Database Connectivity (ODBC), you use the same basic constructions. You will use what you learned today and yesterday repeatedly as you work with SQL.
Why are you constantly telling me to check my implementation? I thought there was a standard!
There is an ANSI standard (the most recent version was released in early 1999); however, most vendors modify it somewhat to suit their databases. The basics are similar if not identical, and each instance has extensions that other vendors copy and improve. We have chosen to use ANSI as a starting point and to point out the differences as we go along.