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laravel模型怎么使用(laravel5.1框架model类查询的实现方法)

更多 时间:2021-10-12 00:14:15 类别:编程学习 浏览量:1039

laravel模型怎么使用

laravel5.1框架model类查询的实现方法

laravel框架model类查询实现:

User::where(['uid'=8])->get();

User类继承自Model类:Illuminate\Database\Eloquent\Model

当User类静态调用where方法时,自动调用了Model里的魔术方法:

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  • public static function __callStatic($method, $parameters)
  • {
  •   $instance = new static; //这里的$instance就是User类的实例对象
  •  
  •   return call_user_func_array([$instance, $method], $parameters);
  • }
  • 相当于调用了user对象的where方法,这时就又调用了魔术方法:

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  • public function __call($method, $parameters)
  • {
  •   if (in_array($method, ['increment', 'decrement'])) {
  •     return call_user_func_array([$this, $method], $parameters);
  •   }
  •  
  •   $query = $this->newQuery(); //返回Illuminate\Database\Eloquent\Builder对象
  •  
  •   return call_user_func_array([$query, $method], $parameters);
  • }
  • 相当于调用Illuminate\Database\Eloquent\Builder对象里的where方法和get方法,这两个方法里其实

    其实是封装调用了Illuminate\Database\Query\Builder对象里的where方法和get方法->get方法里调用了runselect方法

    runSelect方法:

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  • /**
  •  * Run the query as a "select" statement against the connection.
  •  *
  •  * @return array
  •  */
  • protected function runSelect()
  • {
  •   return $this->connection->select($this->toSql(), $this->getBindings(), ! $this->useWritePdo); //调用connection 对象的select方法
  • }
  • 再看connection对象是怎么传到Illuminate\Database\Eloquent\Builder类实例里的:

    Model类的newQuery方法:

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  • /**
  •  * Get a new query builder for the model's table.
  •  *
  •  * @return \Illuminate\Database\Eloquent\Builder
  •  */
  • public function newQuery()
  • {
  •   $builder = $this->newQueryWithoutScopes();
  •  
  •   return $this->applyGlobalScopes($builder);
  • }
  • Model类的newQueryWithoutScopes方法:

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  • /**
  •  * Get a new query builder that doesn't have any global scopes.
  •  *
  •  * @return \Illuminate\Database\Eloquent\Builder|static
  •  */
  • public function newQueryWithoutScopes()
  • {
  •   $builder = $this->newEloquentBuilder(
  •     $this->newBaseQueryBuilder() //这个方法返回
  •   );
  •  
  •   // Once we have the query builders, we will set the model instances so the
  •   // builder can easily access any information it may need from the model
  •   // while it is constructing and executing various queries against it.
  •   return $builder->setModel($this)->with($this->with);
  • }
  • Model类的newBaseQueryBuilder方法实现

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  • /**
  •  * Get a new query builder instance for the connection.
  •  *
  •  * @return \Illuminate\Database\Query\Builder
  •  */
  • protected function newBaseQueryBuilder()
  • {
  •   $conn = $this->getConnection(); \\连接数据库并返回connection对象
  •  
  •   $grammar = $conn->getQueryGrammar();
  •  
  •   return new QueryBuilder($conn, $grammar, $conn->getPostProcessor()); //Illuminate\Database\Query\Builder
  •  
  • }
  • Model类的$resolver属性(连接解析器)的设定是通过

    Illuminate\Database\DatabaseServiceProvider 里的boot方法设置的

    这样Model类的getConnection方法实际调用的DatabaseManager类的connection方法,返回connection类实例

    如何创建的数据库连接:

    Model类getConnection方法->DatabaseManager类connection方法->

    ->ConnectionFactory类的createSingleConnection()

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  • /**
  •  * Create a single database connection instance.
  •  *
  •  * @param array $config
  •  * @return \Illuminate\Database\Connection
  •  */
  • protected function createSingleConnection(array $config)
  • {
  •   //创建连接器对象并连接数据库返回pdo对象
  •   $pdo = $this->createConnector($config)->connect($config);
  •   //传入PDO对象、并返回connection对象,connection对象负责查询数据库
  •   return $this->createConnection($config['driver'], $pdo, $config['database'], $config['prefix'], $config);
  •  
  • }
  • 以上这篇laravel5.1框架model类查询的实现方法就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持开心学习网。

    原文链接:https://www.cnblogs.com/dongruiha/p/6276809.html

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