differences between prepare(stmt) and query(stmt) results

[Donald Leslie]

I wanted to run a query where tested values changed in a loop.

Code was as follows:

query = 'SELECT meetings.meetings_key, meetings.meetings_date, meetings.title ' +
'FROM meetings, meeting_types ' +
'WHERE meetings.type_key = meeting_types.meeting_types_key ' +
"and meeting_types.meeting_type = ? " +
" AND year(meetings.meetings_date) >= ? " +
'ORDER BY meetings.meetings_key'

sth = @dbh.prepare(query)
type = 'Board'
year = '2012'
sth.execute(type,year)
row = sth.fetch
puts "#{sth} , #{row.class} - #{row}"
puts "#{row[0].class} , #{row[1].class} , #{row[2].class}"

This resulted in the following result:

#<Mysql::Stmt:0x00000000affff0> , Array - [6, #<Mysql::Time:2012-01-11 00:00:00>, "Jan board meeting"]
Fixnum , Mysql::Time , String

The result has the data typed as it will be used.
I wanted to be able to get the result as a hash, but fetch_hash was not available.
Looking further I found that fetch_hash is only available if I used query(stmt).

Running the following works:

query = 'SELECT meetings.meetings_key, meetings.meetings_date, meetings.title ' +
'FROM meetings, meeting_types ' +
'WHERE meetings.type_key = meeting_types.meeting_types_key ' +
"and meeting_types.meeting_type = \'Board\' " +
" AND year(meetings.meetings_date) >= \'2012\' " +
'ORDER BY meetings.meetings_key'

sth = @dbh.query(query)
row = sth.fetch_row
puts "#{sth} , #{row.class} - #{row}"
puts "#{row[0].class} , #{row[1].class} , #{row[2].class}"

But this returns :

#<Mysql::Result:0x00000000aff938> , Array - ["6", "2012-01-11", "Jan board meeting"]
String , String , String

Why the difference? I would really like to ba able to use fetch_hash with a
prepared statement or get the data in the form of the prepare results.