On Tue, 26 Feb 2008, [EMAIL PROTECTED] wrote:
Hi,
I am having a problem, in which I couldn't get the relationship column data by
using prefetch.
My relationship is declared like this, suppose we have two tables: railway and
railway_station, which relationship is 1 to many.
#in railway schema
__PACKAGE__->has_many(
"railway_station",
"Schema::RailwayStation",
{ "foreign.railway_station_railway_id" => "self.railway_id" },
);
#in railway_station schema
__PACKAGE__->belongs_to(
"railway",
"Schema::Railway",
{ "foreign.railway_id" => "self.railway_station_railway_id" },
);
My prefetch command is as follows:
my $railways = $schema->resultset('Railway')->search(
{
'me.railway_id' => { 'IN' => $selected_railway_ids },
},
{
join => 'railway_station',
prefetch => 'railway_station',
}
);
I could get the values of the columns of the railways correctly, but not the
columns of railway_stations.
You don't tell us *how* you are trying to get the columns of the railway
stations, so I really cant tell you where you have gone wrong. Your search
code is correct.
You can check what SQL it actually runs and try it for yourself, by
setting DBIC_TRACE=1 in your test script environment.
If I use 'join' only though, I could get all the data for railways which only
have 1 row of railway_station, but not for
railways which have more than 1 rows of railway_station.
Any ideas why this happened ?
Sounds like you are accessing the data incorrectly.
I have a hunch that maybe it's the ID of the railway_station that is causing
this problem. In our current database, the primary key of
railway_station works as a dummy field, in which there are a lot of null values
(although they are primary keys).
Of course, I have my own objections to this current implementation, but I am
wondering if that is indeed the problem, since the primary key of
railway_station isn't supposed to be used in any query generated above ?
Well, it wont fetch the ones with null relation values, obviously.. but
would you expect it to?
Or maybe I am missing something else here.
Like giving us your code? ;)
Jess
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