From: Luc Traonmilin <luc.traonmilin@...>
Date: 2009-03-14T22:46:45+09:00
Subject: Re: Cannot fetch from database using if...else

 From the API doc:
fetch():
Fetch the next row in the result set. DBD Required.

So someone will correct me if I'm wrong but I think you cannot evaluate 
fetch in a condition and call it in the condition itself because it will 
refer to the next row in the result set, probably nil in your case 
because there is only one row.

Luc

Arun Kumar a 辿crit :
> Hi,
> I'm new to ruby and right now i'm trying out some examples involving
> database access using the dbi module. This is my code...
>
> #!/usr/local/bin/ruby -w
>
> require 'dbi'
>
> begin
> con = DBI.connect("DBI:Mysql:Sample:localhost", "arunkumar", "123456")
> stats = con.prepare("Select * from hello where first_name = ?")
> stats.execute('arun')
> if stats.fetch == nil
>     puts "No Records"
>     con.rollback
> else
>     puts stats.fetch
> end
> rescue DBI::DatabaseError => e
>     puts "Error: #{e.errstr}"
> ensure
>     con.disconnect if con
> end
>
> If I use 'puts stats.fetch' before if the fetched data is displayed
> properly. But if i use 'puts stats.fetch' inside if or else 'nil' will
> be displayed even if there are matching records in the database. I dont
> know why. Can anybody help me?????
>
> Regards
> Arun Kumar
>