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服务器之家。

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