php - Codeigniter 数据库查询告诉错误+格式

Question

我选择了一个表，但在错误部分显示我选择了另一张表。我不知道为什么会发生这种情况。我在某些 View 中进行查询，但没有问题。这个问题并不存在于所有地方.但是在一些 View 和 Controller 中。

这是我的 MY_Model

protected function from()
    {
        return $this->db->from($this->_table_name);
    }

    protected function where()
    {
        if(is_array($this->_where))
        {
            foreach($this->_where as $where)
            {
                return $this->db->where($where['field_name'],$where['primary_key']);
            }
        }
        else
        {
            return $this->db->where($this->_field_name,$this->_primary_key);
        }
    }

    protected function or_where()
    {
        if(is_array($this->_where))
        {
            foreach($this->_where as $where)
            {
                return $this->db->or_where($where['field_name'],$where['primary_key']);
            }
        }
        else
        {
            $this->db->or_where($this->_or_field_name,$this->_or_primary_key);
        }
    }

    protected function join()
    {
        if(is_array($this->_join))
        {
            foreach($this->_join as $join)
            {
                return $this->db->join($join['table'],$join['query']);
            }
        }
        else
        {
            return 'Invalid Query';
        }
    }

    protected function order()
    {
        //print_r($this->_order);exit();
        if(is_array($this->_order))
        {
            return $this->db->order_by($this->_order['by'],$this->_order['order']);
        }
        else
        {
            return "Invalid Query";
        }
    }

    protected function limit()
    {
        if(is_array($this->_limit))
        {
            foreach($this->_limit as $limit)
            {
                return $this->db->limit($limit['from'],$limit['to']);
            }
        }
        else
        {
            return $this->db->limit($this->_limit);
        }
    }

    public function get()
    {
        $this->db->select('*');
        if($this->_table_name)
        {
            $this->from();
        }
        if($this->_where || ($this->_field_name && $this->_primary_key))
        {
            $this->where();
        }
        if($this->_or_where || ($this->_or_field_name && $this->_or_primary_key))
        {
            $this->or_where();
        }
        if($this->_join)
        {
            $this->join();
        }
        if($this->_order)
        {
            $this->order();
        }
        if($this->_limit)
        {
            $this->limit();
        }

        return $this->db->get();
    }

这是我的查询

    $this->cm->_table_name = "products";
            $this->cm->_field_name = "products.productID";
            $this->cm->_primary_key = $productID;
            $this->cm->_join = array
            (
                array
                (
                    'table' => 'product_details',
                    'query' => 'products.productID=product_details.productID',
                    'type' => 'left',
                ),
            );
            $data['product'] = $this->cm->get();

这是错误

Error Number: 1064

You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '* FROM 'products', 'parentcategory' WHERE 'products'.'productID' = '30'' at line 1

SELECT *, * FROM `products`, `parentcategory` WHERE `products`.`productID` = '30'

Filename: C:/xampp/htdocs/mv/system/database/DB_driver.php

Line Number: 691

我不知道为什么会发生这种情况，请帮助我。

Answer 1

更改您的查询如下:

SELECT products.*, parentcategory.* FROM `products`, `parentcategory` WHERE `products`.`productID` = '30'

或

SELECT * FROM `products`, `parentcategory` WHERE `products`.`productID` = '30'

您可以添加另一个参数，例如:

$this->cm->_field_to_select = "products.*,parentcategory.*";

并将其添加到您的 get 方法中

if ($this->_field_to_select) {
    $this->db->select($this->_field_to_select);     
}
else {  
    $this->db->select('*');
}