消息：类stdClass的对象无法在codeigniter中转换为字符串

When I run the code below

  $data = array(
                'name' => $this->input->post('name'),
                'recipe' => $this->input->post('recipe'),
                'category_id' => $category_id,
                'recipe_elements' => $this->input->post('recipe_elements'),
                'country' => $this->input->post('country'),
                'video' => $this->input->post('video'),
                'img' => $img_name,
                'vote' => $this->input->post('oy')
            );

            $this->db->insert('recipes',$data);

I get this error

A PHP Error was encountered Severity: 4096
Message: Object of class stdClass could not be converted to string Filename: mysql/mysql_driver.php Line Number: 552 Error Number: 1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' '

I already tried to change the input values but still getting the same error. Any help would be appreciated. How can I fix this?

You're trying to convert an object to a string.Please make sure $category_id and $img_name is not an object.

Take a look here this may help you. Object of class stdClass could not be converted to string

You can sse:$this->db->last_query(); which Returns the last query that was run (the query string, not the result). From where you can see easily your query string which also help you findout actual error.