使用$ this-> db-> count_all_results时出错；作为对布尔值成员函数num_rows的调用

问题描述

在我的模型中，我有一个函数可以根据category_id获取产品数量

public function products_count($category_id,$subcategory_id = null,$brand_id = null)
{
    if ($category_id) {
        $this->db->where('category_id',$category_id);
    }
    if ($subcategory_id) {
        $this->db->where('subcategory_id',$subcategory_id);
    }
    if ($brand_id) {
        $this->db->where('brand',$brand_id);
    }
    $this->db->where('hide_pos !=',1);
    $this->db->from('products');
    return $this->db->count_all_results();
}

我收到错误消息

An uncaught Exception was encountered

Type: Error

Message: Call to a member function num_rows() on boolean

Filename: /var/www/html/projects/demo/system/database/DB_query_builder.PHP

Line Number: 1429

Backtrace:

File: /var/www/html/projects/demo/app/models/admin/Pos_model.PHP
Line: 158
Function: count_all_results 

错误的问题是什么？谢谢

解决方法

为什么不使用$this->db->num_rows()代替$this->db->count_all_results()，结果更准确，我正在重写您的函数，请尝试此操作。

public function products_count($category_id,$subcategory_id = null,$brand_id = null)
{
    $this->db->from('products');
    if ($category_id) {
        $this->db->where('category_id',$category_id);
    }
    if ($subcategory_id) {
        $this->db->where('subcategory_id',$subcategory_id);
    }
    if ($brand_id) {
        $this->db->where('brand',$brand_id);
    }
    $this->db->where('hide_pos !=',1);
    $this->db->get();
    return $this->db->num_rows();
}

如果您想使用自己的代码，只需将$this->db->from('products')放在最前面，希望它也能正常工作。

,

如果我要请您使用Codeigniter 4，请确保。请在下面使用它。我认为这将帮助您解决此问题。 如果要扩展到Codeigniter核心模型，则不需要$this->db。只是

扩展到Codeigniter核心模型，使用

public function products_count($category_id,$brand_id = null)
{
    $query = $this->table('products'); // self::table('products')

    if ($category_id) {
        $query = $query->where('category_id',$category_id);
    }
    if ($subcategory_id) {
        $query = $query->where('subcategory_id',$subcategory_id);
    }
    if ($brand_id) {
        $query = $query->where('brand',$brand_id);
    }
    $query = $query->where('hide_pos !=',1);
    
    return $query->countAllResults();
}

如果不扩展到Codeigniter Core模型，请使用

public function __construct()
{
    $this->db = db_connect();
}
public function products_count($category_id,$brand_id = null)
{
    $query = $this->db->table('products');

    if ($category_id) {
        $query = $query->where('category_id',1);
    
    return $query->countAllResults();
}

如果您使用的是您所说的codeigniter 3，请使用此

public function products_count($category_id,$brand_id = null)
{
    $query = $this->db->from('products');

    if ($category_id) {
        $query = $query->where('category_id',1);
    
    return $query->count_all_results();
}

OR

public function products_count($category_id,1)->get();
    
    return $query->num_row();
}

我希望这种帮助不引起我的注意