带有引用的 call_user_func_array [英] call_user_func_array with references

问题描述

我基本上是在尝试调用 mysqli::bind_param 通过 call_user_func_array.

I'm basically trying to call mysqli::bind_param via call_user_func_array.

这是我的功能:

function Insert($table, $values=array(), $flags=0) {
    $field_count = count($values);

    if($field_count > 0) {
        $fields = implode(',',array_keys($values));
        $placeholders = implode(',',array_repeat('?',$field_count));
    } else {
        $fields = '';
        $placeholders = '';
    }

    if($flags > 0) {
        $flag_arr = array();
        if($flags & self::LOW_PRIORITY) $flag_arr[] = 'LOW_PRIORITY';
        if($flags & self::DELAYED) $flag_arr[] = 'DELAYED';
        if($flags & self::HIGH_PRIORITY) $flag_arr[] = 'HIGH_PRIORITY';
        if($flags & self::IGNORE) $flag_arr[] = 'IGNORE';
        $flags_str = implode(' ',$flag_arr);
    } else {
        $flags_str = '';
    }

    $sql = "INSERT $flags_str INTO $table ($fields) VALUES ($placeholders)";
    $stmt = $this->mysqli->prepare($sql);
    if($stmt === false) {
        throw new Exception('Error preparing MySQL statement.<br/>MSG: '.$this->mysqli->error.'<br/>SQL: '.$sql);
    }

    if($field_count > 0) {
        $types = '';
        foreach($values as $val) {
            if(is_int($val)) $types .= 'i';
            elseif(is_float($val)) $types .= 'd';
            elseif(is_string($val)) $types .= 's';
            else $types .= 'b';
        }
        $params = array_merge(array($types),array_values($values));
        call_user_func_array(array($stmt,'bind_param'),$params);
    }

    $stmt->execute();
    return $stmt;
}

问题发生在 call_user_func_array 行上.我收到此错误:

The problem occurs on the call_user_func_array line. I get this error:

mysqli_stmt::bind_param() 的参数 2 应为引用，给定值

Parameter 2 to mysqli_stmt::bind_param() expected to be a reference, value given

我明白这个问题，只是不知道如何解决.

I understand the problem, I'm just not sure how to work around it.

举个例子，函数可以这样调用:

As an example, the function may be called like this:

$db->Insert('pictures',array('views'=>1));

并且 var_dump($params) 会产生这个:

array
  0 => string 'i' (length=1)
  1 => int 1

那么，有没有办法用可变数量的参数调用mysqli::bind_param，或者以某种方式使我的数组成为引用?

So, is there a way to call mysqli::bind_param with a variable number of arguments, or somehow make my array into references?

推荐答案

mysqli_stmt::bind_param() 状态:

将 mysqli_stmt_bind_param() 与 call_user_func_array() 结合使用时必须小心.请注意，mysqli_stmt_bind_param() 需要通过引用传递参数，而 call_user_func_array() 可以接受可以表示引用或值的变量列表作为参数.

Care must be taken when using mysqli_stmt_bind_param() in conjunction with call_user_func_array(). Note that mysqli_stmt_bind_param() requires parameters to be passed by reference, whereas call_user_func_array() can accept as a parameter a list of variables that can represent references or values.

有一个解决方案 发布在手册的用户评论部分.简而言之，您创建了一个函数，该函数接受一个数组并返回一个重复数组，该数组的元素是对源数组中元素的引用.

There is a solution posted in the user-comments section in the manual. In short, you make a function that accepts an array and returns a duplicate array whose elements are references to the elements in the source array.

原来有几个SO 对此的问题.

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