在Laravel的'join'或'where'中使用'='有什么区别吗？

Question

I have used both ways:

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

and:

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

and for me it has worked the same either adding or removing the = sign. Does anybody know if this is allowed? If so, what's the best way to do it? Thanks.

Answer 1

According to the function definition in the source:

// 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.

So you can see, if you omit the = as the second argument, the query builder will place it there by default, which is consistent with the behavior you describe.

Reference

Answer 2

This is fine, the '=' is the default operator in the query builder.

See https://github.com/laravel/framework/blob/5.5/src/Illuminate/Database/Query/Builder.php#L497 for source of the 'where' code. It assumes that if 2 arguments exist, it is the equals operator.