DBIx::Class -- creating unique rows in sub-table - sql

Question

My (simplified) SQLite tables are like this:
create table customers (
id integer primary key autoincrement,
contact_name text,
billaddr_id integer references addresses(id)
);
create table addresses (
id integer primary key autoincrement,
address text
);
And here are the result classes (generated from the sql by dbicdump):
Test::DB::Schema::Result::Customer->table("customers");
Test::DB::Schema::Result::Customer->add_columns(
"id",
{ data_type => "integer", is_auto_increment => 1, is_nullable => 0 },
"contact_name",
{ data_type => "text", is_nullable => 1 },
"billaddr_id",
{ data_type => "integer", is_foreign_key => 1, is_nullable => 1 },
);
Test::DB::Schema::Result::Customer->set_primary_key("id");
Test::DB::Schema::Result::Address->table("addresses");
Test::DB::Schema::Result::Address->add_columns(
"id", { data_type => "integer", is_auto_increment => 1, is_nullable => 0 },
"address", { data_type => "text", is_nullable => 1 },
);
Test::DB::Schema::Result::Address->set_primary_key("id");
Test::DB::Schema::Result::Address->has_many(
"customers",
"Test::DB::Schema::Result::Customer",
{ "foreign.billaddr_id" => "self.id" },
{ cascade_copy => 0, cascade_delete => 0 },
);
Test::DB::Schema::Result::Customer->belongs_to(
"billaddr",
"Test::DB::Schema::Result::Address",
{ id => "billaddr_id" },
{
is_deferrable => 0,
join_type => "LEFT",
on_delete => "NO ACTION",
on_update => "NO ACTION",
},
);
This bit of code:
my $data = {
contact_name => 'Jim Customer',
billaddr => {
address => 'Address...',
},
};
my $newcustomer = $c->schema->resultset('Customer')->create($data);
results in this database update:
SELECT me.id, me.address FROM addresses me WHERE ( ( me.address = ? ) ): 'Address...'
BEGIN WORK
SELECT me.id, me.address FROM addresses me WHERE ( ( me.address = ? ) ): 'Address...'
INSERT INTO addresses ( address ) VALUES ( ? ): 'Address...'
INSERT INTO partners ( billaddr_id, contact_name ) VALUES ( ?, ? ) : '10', 'Jim Customer'
COMMIT
Why does it do a select before the insert? Because it's checking to see if an address with the same value of the 'address' column already exists. If it does exist, the ID of that address is reused, like this:
SELECT me.id, me.address FROM addresses me WHERE ( ( me.address = ? ) ): 'Address...'
INSERT INTO partners ( billaddr_id, contact_name ) VALUES ( ?, ? ): '10', 'Another Customer with the same address'
But that's not what I want! I want separate addresses for separate customers, even if they happen to live in the same place at the moment.
How can I make DBIx::Class create a new row in the addresses table every time?

Answer 1

Thanks to abraxxa's comments, I've been pointed in the right direction and have done more reading and testing with DBIx::Class:Schema.
Generating the table from the Schema classes, rather than the other way round, seems like the way to go, especially if it will make future upgrades to the database easier.
I've boiled the problem down to the following example code:
Test.pl:
#!/usr/bin/perl
use Test::DB::Schema;
my $schema = Test::DB::Schema->connect(
"dbi:SQLite:dbname=dbicsl_test.db", '', '', {}
);
$schema->deploy({ add_drop_table => 1 } , '.');
$schema->storage->debug(1);
my $data1 = {
text => 'Fred',
table2 => {
text => 'abc',
}
};
my $new1 = $schema->resultset('Table1')->create($data1);
my $data2 = {
text => 'Jim',
table2 => {
text => 'xyz',
}
};
my $new2 = $schema->resultset('Table1')->create($data2);
my $data3 = {
text => 'Emily',
table2 => {
text => 'abc',
}
};
my $new3 = $schema->resultset('Table1')->create($data3);
Test::DB::Schema::Result::Table1.pm:
package Test::DB::Schema::Result::Table1;
use base 'DBIx::Class::Core';
__PACKAGE__->table("table1");
__PACKAGE__->add_columns(
"id",
{ data_type => "integer", is_auto_increment => 1, is_nullable => 0 },
"text",
{ data_type => "text", is_nullable => 1 },
"table2_id",
{ data_type => "integer", is_foreign_key => 1, is_nullable => 0 },
);
__PACKAGE__->set_primary_key("id");
__PACKAGE__->has_one(
table2 =>
"Test::DB::Schema::Result::Table2",
{ 'foreign.id' => 'self.table2_id' },
);
1;
Test::DB::Schema::Result::Table2:
package Test::DB::Schema::Result::Table2;
use base 'DBIx::Class::Core';
__PACKAGE__->table("table2");
__PACKAGE__->add_columns(
"id",
{ data_type => "integer", is_auto_increment => 1, is_nullable => 0 },
"text",
{ data_type => "text", is_nullable => 0 },
);
__PACKAGE__->set_primary_key("id");
1;
And here's the output:
SELECT me.id, me.text FROM table2 me WHERE ( me.text = ? ): 'abc'
BEGIN WORK
SELECT me.id, me.text FROM table2 me WHERE ( me.text = ? ): 'abc'
INSERT INTO table2 ( text) VALUES ( ? ): 'abc'
INSERT INTO table1 ( table2_id, text) VALUES ( ?, ? ): '1', 'Fred'
COMMIT
SELECT me.id, me.text FROM table2 me WHERE ( me.text = ? ): 'xyz'
BEGIN WORK
SELECT me.id, me.text FROM table2 me WHERE ( me.text = ? ): 'xyz'
INSERT INTO table2 ( text) VALUES ( ? ): 'xyz'
INSERT INTO table1 ( table2_id, text) VALUES ( ?, ? ): '2', 'Jim'
COMMIT
SELECT me.id, me.text FROM table2 me WHERE ( me.text = ? ): 'abc'
INSERT INTO table1 ( table2_id, text) VALUES ( ?, ? ): '1', 'Emily'
So the database now looks like
table1.id table1.text table1.table2_id
1 Fred 1
2 Jim 2
3 Emily 1
table2.id table2.text
1 abc
2 xyz
whereas I expected / hoped for:
table1.id table1.text table1.table2_id
1 Fred 1
2 Jim 2
3 Emily 3
table2.id table2.text
1 abc
2 xyz
3 abc
Why does it reuse 1/abc when I haven't told it to make the table2.text column unique?