这种架构和DBIC代码是否有效？

时间：2013-11-12 10:54:27

标签： mysql sql perl schema dbix-class

我正在尝试确定我是否正在使用SQL和DBIx :: Class接近以下问题，因为我对这两者都很新。

我有一个包含3个表的模式，设备，对象和网络

设备可以有0..1到多个对象 一个对象可以有1个网络但网络可以属于0 ...许多设备。

我试图在图片中显示的架构中捕获这种关系。

enter image description here

这是相关的Schema。

设备

__PACKAGE__->table("Device");

__PACKAGE__->add_columns(
  "devicename",
  { data_type => "varchar", is_nullable => 0, size => 50 },
  "devicetype",
  { data_type => "varchar", is_nullable => 0, size => 20 },
  "deviceid",
  {  data_type => "integer", is_auto_increment => 1, is_nullable => 0 },
);

__PACKAGE__->set_primary_key("deviceid");
__PACKAGE__->has_many(
  "objects",
  "TestApp::Schema::Result::Object",
  { "foreign.device_deviceid" => "self.deviceid" },
  { cascade_copy => 0, cascade_delete => 0 },

对象

__PACKAGE__->table("Object");

__PACKAGE__->add_columns(
  "objectid",
  { data_type => "integer", is_auto_increment => 1, is_nullable => 0 },
  "objectname",
  { data_type => "varchar", is_nullable => 0, size => 100 },
  "objecttype",
  { data_type => "varchar", is_nullable => 0, size => 20 },
  "device_deviceid",
  {  data_type => "integer", is_foreign_key => 1, is_nullable => 0 },
  "network_networkid",
  {    data_type => "integer", is_foreign_key => 1, is_nullable => 1 },
);

__PACKAGE__->set_primary_key("objectid");

__PACKAGE__->belongs_to(
  "device_deviceid",
  "TestApp::Schema::Result::Device",
  { deviceid => "device_deviceid" },
  { is_deferrable => 1, on_delete => "NO ACTION", on_update => "NO ACTION" },
);

 __PACKAGE__->belongs_to(
  "network_networkid",
  "TestApp::Schema::Result::Network",
  { networkid => "network_networkid" },
  {
    is_deferrable => 1,
    join_type     => "LEFT",
    on_delete     => "NO ACTION",
    on_update     => "NO ACTION",
  },
);

网络

__PACKAGE__->table("network");

__PACKAGE__->add_columns(
   "networkid",
 { data_type => "integer", is_auto_increment => 1, is_nullable => 0 },
  "network",
  { data_type => "varchar", is_nullable => 1, size => 15 },
  "netmask",
  { data_type => "varchar", is_nullable => 1, size => 15 },
  "cidr",
   { data_type => "integer", is_nullable => 1 },
 );

__PACKAGE__->set_primary_key("networkid");

__PACKAGE__->has_many(
 "objects",
  "TestApp::Schema::Result::Object",
  { "foreign.network_networkid" => "self.networkid" },
  { cascade_copy => 0, cascade_delete => 0 },
);

对于我的测试数据，我正在插入如下所示的数据。有更有效的方法吗？

#get result sets
my $network_rs = $schema->resultset('Network');
my $device_rs = $schema->resultset('Device');

#create a new device
my $new_device = $device_rs->create( { devicename => 'test_device', devicetype => 'test_dt'});

#create a new network if it doesn't exist.
my $new_network = $network_rs->find_or_create({ network => '1.1.1.1', netmask => '255.255.255.0', cidr => '24' });

#Add two objects and set the foreign key for the network table for the newly created network above.
$new_device->objects->create( { objectname => 'networkobj1',network_networkid => $new_network->networkid });
$new_device->objects->create( { objectname => 'networkobj2',network_networkid => $new_network->networkid });

要查看分配给每个网络的网络，我只需执行以下操作; 

my @deviceObjects = $new_device->objects();

foreach my $object (@deviceObjects) 
{ 
print $object->objectname . " contains the following network:\n";  
print $object->network_networkid->network . "\n";
print $object->network_networkid->netmask . "\n";
print $object->network_networkid->cidr . "\n";
}

2 个答案:

答案 0 :(得分：3)

基本上你做的一切都是正确的。 您的对象表通常称为桥接器或多对多辅助表。 要直接从设备到其网络，您可以添加many_to_many帮助器方法，请参阅DBIx :: Class :: Relationship文档。 有一些模块可以用（测试）数据填充数据库，例如DBIx :: Class :: Fixtures。

对于返回单行（belongs_to，has_one和might_have）的关系以及返回a行列表（has_many）。 使用device-＆gt; objects-＆gt;网络读取更加自然，包括存储外键的列的名称没有多大意义。

除了那些小事，还有一个好的开始！ 在irc.perl.org中加入＃dbix-class以获得实时帮助。

答案 1 :(得分：0)

重新插入测试数据，有一种更有效的方式（编写它），DBIC可以根据你告诉它的关系一次完成一大堆插入，我们称之为“multireate”，所以使用你的例子：

# get main device resultset:
my $device_rs = $schema->resultset('Device');

# create all the things:
$device_rs->create({ 
   # Device columns:
   devicename => 'test_device', 
   devicetype => 'test_dt',
   # Objects:
   objects => [
     {
        objectname => 'networkobj1',
        # network for this object:
        network_networkid => {
           network => '1.1.1.1', netmask => '255.255.255.0', cidr => '24',
        }
     },
     {
        objectname => 'networkobj2',
        # network for this object:
        network_networkid => {
           network => '1.1.1.1', netmask => '255.255.255.0', cidr => '24',
        }
     }
   ]
});

请注意，指定网络数据不应该为您提供两个插入的网络行，它将使用find_or_new来创建该行，因此应找到为第二个创建的第一个行。

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