Learning by doing

Recently, a reader saw my fix for SQL Server booleans, and asked me a followup question: why does Rails display a yes/no selection instead of a checkbox? The short answer is look in {RUBY_HOME} /lib/ruby/gems/1.8 /gems/actionpack-1.10.2 /lib/action_view/helpers, but your path may vary depending on whether you are using gem, "edge rails", etc. Anyway, look in the file "active_record_helper.rb" for a method called "all_input_tags", and notice that it calls "default_input_block" if you don't supply an input_block. Now notice that "default_input_block" creates a label and calls "input(record, column.name)" which in turn calls "InstanceTag#to_tag" which finally looks at the datatype and maps boolean to a select tag. Perhaps a wiser Rails explorer can provide us with the rationale for this, but I guess we could add a MixIn for InstanceTag that redefines the to_tag() method, or just do a dirty and unmaintainable hack l...

I finally helped some friends set up a data cube. It mostly involved creating a specialized view that had one numeric field (in our case - a count), a date field, and a number of categorical "dimension" fields. We used Seagate Info , now from Business Objects to actually work with the data. So no, I didn't write my own data cube explorer. The client couldn't afford that, and I didn't really want to do it. What did I do? I took a conglomerated (non-normalized) survey table and built a set of relational tables for surveys, questions, answers, results (the actual answers), etc. Then I wrote an "importer" to smartly read the "scanned surveys" table and populate my relational data set with any "new" surveys, based on an "IsProcessed" flag, and whether that ScannedSurvey_ID existed in the relational table collection. This allows their OCR process to add records at any time, and a daily process runs under SQL Agent to import new s...