在Laravel的'join'或'where'中使用'='有什麼區別？

Question

我用兩種方式：

$this->data = DB::table('projects') 
    ->select('companies_info.*', 'project_roles_types.name AS project_role_name') 
    ->join('project_companies_members', 'project_companies_members.project_id', 'projects.project_id') 
    ->where($some_variable, $project_id) 
    ->get(); 

和：

$this->data = DB::table('projects') 
    ->select('companies_info.*', 'project_roles_types.name AS project_role_name') 
    ->join('project_companies_members', 'project_companies_members.project_id', '=', 'projects.project_id') 
    ->where($some_variable, '=', $project_id) 
    ->get(); 

，對我來說已經工作過的相同或者添加或刪除=跡象。 有人知道這是否允許？如果是這樣，那麼最好的辦法是什麼？ 謝謝。

Answer 1

據源函數定義：

// Here we will make some assumptions about the operator. If only 2 values are 
// passed to the method, we will assume that the operator is an equals sign 
// and keep going. Otherwise, we'll require the operator to be passed in. 

所以你可以看到，如果你忽略了=作爲第二個參數，查詢生成器將其置於默認情況下，這是一致的你描述的行爲。

Reference

Answer 2

這很好，'='是查詢生成器中的默認操作符。

請參閱https://github.com/laravel/framework/blob/5.5/src/Illuminate/Database/Query/Builder.php#L497瞭解「where」代碼的來源。它假定如果存在2個參數，它就是等號運算符。