X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FManual%2FCookbook.pod;h=4dec7ae72222c668ccc677e268fc39982b3e512a;hb=4aeeed8aba0096f1272b29d9dc794714201f232c;hp=f2934cb8d6b6a0171d881ced347946fefb23af3e;hpb=fe5cf259d845b9a7ddb8e75ee514855e12441608;p=dbsrgits%2FDBIx-Class-Historic.git diff --git a/lib/DBIx/Class/Manual/Cookbook.pod b/lib/DBIx/Class/Manual/Cookbook.pod index f2934cb..4dec7ae 100644 --- a/lib/DBIx/Class/Manual/Cookbook.pod +++ b/lib/DBIx/Class/Manual/Cookbook.pod @@ -107,12 +107,15 @@ to access the returned value: ); # Equivalent SQL: - # SELECT name name, LENGTH( name ) name_length + # SELECT name name, LENGTH( name ) # FROM artist -If your alias exists as a column in your base class (i.e. it was added -with C), you just access it as normal. Our C -class has a C column, so we just use the C accessor: +Note that the C< as > attribute has absolutely nothing to with the sql +syntax C< SELECT foo AS bar > (see the documentation in +L). If your alias exists as a +column in your base class (i.e. it was added with C), you +just access it as normal. Our C class has a C column, so +we just use the C accessor: my $artist = $rs->first(); my $name = $artist->name(); @@ -139,7 +142,7 @@ any of your aliases using either of these: select => [ { distinct => [ $source->columns ] } ], - as => [ $source->columns ] + as => [ $source->columns ] # remember 'as' is not the same as SQL AS :-) } ); @@ -176,6 +179,10 @@ L supports C as follows: # LEFT JOIN cd cds ON ( cds.artist = me.artistid ) # GROUP BY name +Please see L documentation if you +are in any way unsure about the use of the attributes above (C< join +>, C< select >, C< as > and C< group_by >). + =head3 Predefined searches You can write your own L class by inheriting from it @@ -415,7 +422,7 @@ ways, the obvious one is to use search: {}, { select => [ { sum => 'Cost' } ], - as => [ 'total_cost' ], + as => [ 'total_cost' ], # remember this 'as' is for DBIx::Class::ResultSet not SQL } ); my $tc = $rs->first->get_column('total_cost'); @@ -487,7 +494,7 @@ To order C<< $book->pages >> by descending page_number. =head2 Transactions As of version 0.04001, there is improved transaction support in -L and L. Here is an +L and L. Here is an example of the recommended way to use it: my $genus = $schema->resultset('Genus')->find(12); @@ -526,7 +533,7 @@ in the future. =head2 Many-to-many relationships -This is straightforward using L: +This is straightforward using L: package My::DB; # ... set up connection ... @@ -568,7 +575,9 @@ C. $attrs->{foo} = 'bar' unless defined $attrs->{foo}; - $class->next::method($attrs); + my $new = $class->next::method($attrs); + + return $new; } For more information about C, look in the L @@ -586,7 +595,7 @@ module. To make an object stringify itself as a single column, use something like this (replace C with the column/method of your choice): - use overload '""' => 'foo', fallback => 1; + use overload '""' => sub { shift->name}, fallback => 1; For more complex stringification, you can use an anonymous subroutine: @@ -905,7 +914,7 @@ method. =head2 Profiling -When you enable L's debugging it prints the SQL +When you enable L's debugging it prints the SQL executed as well as notifications of query completion and transaction begin/commit. If you'd like to profile the SQL you can subclass the L class and write your own profiling @@ -1100,41 +1109,81 @@ B test.pl DBIx::Class is not built for speed, it's built for convenience and ease of use, but sometimes you just need to get the data, and skip the -fancy objects. Luckily this is also fairly easy using -C: - - # Define a class which just returns the results as a hashref: - package My::HashRefInflator; +fancy objects. + +To do this simply use L. + + my $rs = $schema->resultset('CD'); + + $rs->result_class('DBIx::Class::ResultClass::HashRefInflator'); + + my $hash_ref = $rs->find(1); + +Wasn't that easy? + +=head2 Get raw data for blindingly fast results - ## $me is the hashref of cols/data from the immediate resultsource - ## $prefetch is a deep hashref of all the data from the prefetched - ## related sources. +If the C solution above is not fast enough for you, you +can use a DBIx::Class to return values exactly as they come out of the +data base with none of the convenience methods wrapped round them. - sub mk_hash { - my ($me, $rest) = @_; +This is used like so:- - return { %$me, - map { ($_ => mk_hash(@{$rest->{$_}})) } keys %$rest } - }; + my $cursor = $rs->cursor + while (my @vals = $cursor->next) { + # use $val[0..n] here } - sub inflate_result { - my ($self, $source, $me, $prefetch) = @_; - return mk_hash($me, $prefetch); +You will need to map the array offsets to particular columns (you can +use the I