sql_query_generator: Generates SQL SELECT statements from form data

This class can generate a large range of SQL SELECT queries from a submitted form.

It provides means to generate simple queries on one field on a table, joins, selection of fields to be returned, aliasing of fields (eg. SUM(Price) AS Total), ORDER BY, even multiple queries from one form.

Comes with a basic demo file, which I hope to update in time. GROUP BY and HAVING are also provided, but not entirely reliable.

Demo file provides overview of creating forms necessary to generate results.