The nice thing about using SQL is that it tends to make your code portable. The worst thing about it is Microsoft's adoption of the name SQL for their database, SQL Server. That confuses people. SQL is a language that's used to access many databases from Access to MySQL to SQL Server to Oracle. And others. Like most cross-platform languages each platform uses its own super/subset of SQL but if you stick with the ANSI standard then it's usually pretty easy to change the database/back end without rewriting your code. (Since the ANSI standard is sort of a 'lowest common denominator' sticking with it sometimes complicates your code. You need to judge how much of a tradeoff you're willing to make for portability.)

I've done this a couple of times, writing a VB program that runs against an Oracle database and then changing it to run against a SQL Server database. In one case the *only* thing I needed to change was the connection string. In the other case I found that I had actually used some Oracle-specific 'SQL' language & had to rewrite those. But both programs are now standard & I have great hopes that they will now run unchanged (except for the connection string) against any SQL database we choose to use for the back end.