filtersFromURL extracts the filter parameters from the urL, and creates an array of strings for each filter expression found.

mapColumnType converts native Ego types into the equivalent Postgres data types.

With a default user name string, and the current URL, determine if the username should be overridden with one from the URL.

StripQuotes removes double quotes from the input string.

whereClause accepts a list of filter parameters, and converts them to a SQL WHERE clause (including the 'WHERE' token).