Too much Java in here dayum. Here's my (fairly simple) solution in Javascript. Lemme know what y'all think!
edit so you don't have to click the link (o no! :P):
function countLetters(str) { var counts = {}; var ch, len, index, count; for (index = 0; index < str.length; ++index) { ch = str.charAt(index); count = counts[ch]; counts[ch] = count ? count + 1 : 1; } console.log(counts); }
Have a look at a simple ORM - it sounds like your a newbie programmer, so sorry if I've misread the situation.
Something like Django https://www.djangoproject.com/ will give you access to a DB with a prebuilt data entry side, provided you can build the models.
(I think the tutorial includes a restaurant example!)
Excel isn't really a database, but you can probably use that data (after exporting it to a CSV) to populate your models.
https://tutorial.djangogirls.org/en/ this is a very good tutorial to get you started.