bind_param 中的参数数量未知 [英] unknown number of parameters in bind_param

问题描述

当您不知道将要接收的参数数量时，你们会怎么做?

What do you guys do when you don't know the number of parameters that you are going to receive?

例如:

if($a==1) $filter.=" AND u.name = ?";
if($b==1) $filter.=" AND u.address = ?";
if($c==1) $filter.=" AND u.age = ?";
if($d==1) $filter.=" AND u.city = ?";
ETC...

$stmt->prepare("SELECT id
                FROM users u
                WHERE u.cp = ?
                ".$filter);

$stmt->bind_param("i", $cp);

现在呢?如果您收到 $a = 1，您将收到错误消息，因为您只在 bind_param 上传递了 1 个参数.所以你不知道你是否会收到 1、2、3 或 4 个参数，我不想制作很多 IF 或者我必须使用循环来计算参数?

And now? if you are receiving $a = 1 you will get an error because you are only passing 1 parameter on the bind_param. So you don't know if you are going to receive 1, 2, 3 or 4 params and I don't want to make a lot of IF or I must use a loop to count the number of parameters?

推荐答案

您必须在添加条件时管理参数列表(类型和值).这意味着您需要使用 call_user_func_array 将值列表传递给 bind_param.

You'll have to manage the list of arguments (type and value) as you add the conditions. This means you need to use call_user_func_array to pass the list of values to bind_param.

基本上，在您的每个 if 语句中，不仅要添加条件，还要添加参数类型(例如 $types .= 'i')和参数(例如 $args[]=$arg).

Basically, in each of your if statements, not only add the condition, but also add the parameter type (e.g. $types .= 'i') and the parameter (e.g. $args[]=$arg).

您会在 bind_param 文档的此注释中找到一个关于如何执行此操作的好示例:http://www.php.net/manual/en/mysqli-stmt.bind-param.php#109256

You'll find a good example on how to do this in this comment of the bind_param documentation: http://www.php.net/manual/en/mysqli-stmt.bind-param.php#109256

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