Use of fetchall

Ammu has asked for the wisdom of the Perl Monks concerning the following question:

Our requirement is to fetch some rows from a database table and put it in a new hashtable with a specified column as key.

$dbh = DBI->connect("dbi:ODBC:Driver={SQL Server};Server=<Servername>;
+UID=<username>;PWD=<pswd>") ;

my $sth = $dbh->prepare("select id,name,job,location from <databasenam
+e>.employee_relation");
 $sth->execute; 
my $hash = $sth->fetchall_hashref('id'); 
print Dumper($hash);
[download]

When i am using Dumper i will be able to get all tha entries for hashtable.But what if i need to get the value corresponding to a certain key. I tried print "@{$hash{'E200'}}\n"; This if for printing the values corresponding to the id E200.But its not showing any output.Please help.

Comment on Use of fetchall_hashref Select or Download Code

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Re: Use of fetchall_hashref by choroba (Cardinal) on Sep 07, 2012 at 12:06 UTC
`$hash->{id}` contains the value. If you want to dereference it as an array, wrap it into `@{ ... }`. لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l] [select]
Re: Use of fetchall_hashref by Corion (Patriarch) on Sep 07, 2012 at 12:14 UTC
If you only need a certain value for the "id" column, it's best to only query that value from the databases instead of reimplementing the search in Perl.	[reply]
Re: Use of fetchall_hashref by runrig (Abbot) on Sep 07, 2012 at 14:47 UTC
Your `$hash` is a reference to a hash, not a hash. So you would need, e.g.: `print Dumper $hash->{E200}; # Or for a certain column print "$hash->{E200}{job}\n";` [download]	[reply] [d/l] [select]
Re^2: Use of fetchall_hashref by Anonymous Monk on Sep 10, 2012 at 04:16 UTC
hi we tried this `print Dumper $hash->{E200};` But it is returning something like $VAR1 = undef; please help me out :( tried this also `print "$hash->{E200}{job}\n";` But it not printing any value .	[reply] [d/l] [select]
Re^3: Use of fetchall_hashref by runrig (Abbot) on Sep 10, 2012 at 16:25 UTC
Then all I can say is look at the output of: `print Dumper $hash;` [download] and see what the output is, see if 'E200' is in there, etc.	[reply] [d/l]
Re: Use of fetchall_hashref by philiprbrenan (Monk) on Sep 07, 2012 at 13:12 UTC
`say $hash->{E200}` [download]	[reply] [d/l]
Re: Use of fetchall_hashref by frozenwithjoy (Priest) on Sep 07, 2012 at 21:29 UTC
This isn't a direct answer to your problem, but Darin McBride just wrote a demo for DBD::CSV that also covers the problem of restructuring the hashref result from `fetchall_hashref`. It is a good, fast read. The relevant part is: `my %totals; for my $r (@$res) { $totals{ $r->{AcNo}}{$r->{Type} } = $r->{SUM}; }` [download]	[reply] [d/l] [select]
Re: Use of fetchall_hashref by Ravi V (Scribe) on Sep 07, 2012 at 15:20 UTC
Have you tried Sybase::Simple module ..... it has methods which directly returns data in form of hashes	[reply]