Computer Science & Perl Programming

Chapter 59. Using DBI with Microsoft Access

Craig McElwee

The thing about magicians is that they do some rather amazing things and make it look easy. You know it’s not really magic, but without a key secret or two, there is simply no way you can manage the same feat. The same can be said for putting together a little SQL-based web application on Windows; seeing the pros do it in a few paragraphs of documentation makes it look easy, then you try it yourself and it’s no-go.

I once faced this situation. I considered myself a competent Perl programmer who simply hadn’t had yet had the need for a SQL (Structured Query Language) database. I knew I eventually would, but I’d survived with tied hashes and CSV files until then.

ora: CSV files

A CSV (Comma-Separated Values) file is simply a text file with lines containing data separated by commas, like this: Johannes,Smythe,505 Oyster Street,555-1234. This is a good method of saving data in “flat file” (that is, plain old text file) databases, since each line is a record that can be read by a Perl script, and the data extracted by splitting on the commas. Assuming the above line is in a file called addresses.txt, you could do something like this:

	open(IN, "<addresses.txt");

	

	while($line = <IN>) {

	    ($first, $last, $address, $phone) = split /,/, $line;

	    ...mangle data to heart's content...

	}

If there are already commas in your data, this won’t work; you’ll have to either quote the items that have commas in the data, or use a different delimiter, such ...