codeigniter：从数据库编辑和删除 [英] codeigniter: editing and deleting from database
问题描述
我无法在数据库中编辑/删除问题。从我的测验问题。这是我的模型。我想通过控制器从视图编辑一个问题。
这是我目前的模式：
function getquestions ）
{
//获取有关测验的数据 - 我们需要测验大小
$ quiz = $ this-> getquiz（$ quizid）
$ qzsize = $ quiz ['quizsize'];
$ this-> db-> select（'id'）; //我们只需要id字段
$ this-> db-> limit（$ qzsize）; //请问多少个问题
//下一个子句允许我们选择随机问题 - 如何工作的一个完整的讨论，它的缺点是
//这里https ：//www.warpconduit.net/2011/03/23/selecting-a-random-record-using-mysql-benchmark-results/
$ this-> db-> order_by（ 'RAND（）'）;
$ res = $ this-> db-> get_where（'questions'，array（'quizid'=> $ quizid））;
log_message（'DEBUG'，$ this-> db-> last_query（））;
if（$ res-> num_rows（）== 0）{
//没有找到问题！
//返回false到控制器告诉我们遇到错误
//让控制器决定如何处理错误
return false;
}
$ questions = array（）;
foreach（$ res-> result_array（）as $ row）{
$ questions [] = $ row ['id'];
}
shuffle（$ questions）; //以随机顺序提供问题
$ res-> free_result（）;
return $ questions;
}
/ **
*获取问题
* @param int - 问题ID
* @return mixed false | array - 问题数据+答案（数组）
* /
function getquestion（$ id）{
$ this-> db-> where（'id'，$ id）;
$ res = $ this-> db-> get（'questions'）;
if（$ res-> num_rows（）！= 1）{
return false;
}
$ question = $ res-> row_array（）; //获取第一行作为数组 - 这是问题数据
//现在得到这个问题的答案
$ res = $ this-> db-> ; get_where（'answers'，array（'questionid'=> $ id））;
if（$ res-> num_rows（）< 2）{
//必须至少有两个答案
return false;
}
$ answers = array（）;
//将每一行作为一个数组并推送到答案数组
foreach（$ res-> result_array（）as $ row）{
$ answers [] = $ row;
}
shuffle（$ answers）;
//现在返回所有数据作为一个数组，用键帮助访问元素
返回数组（'q'=> $ question，'a'=> $ answers） ;
}
以检测删除动作。这可能是通过URL或通过表单输入。
例如，控制器可能定义为
public function view（$ question_id = 0，$ action =''）{
$ b b
然后，您可能在您的页面上有一个链接，其操作部分定义为删除。在你的控制器，你会有一个<$ p
if（$ action =='delete'）{
要从数据库中删除所选问题，您将使用
$ this-db-where（'question_id'，$ question_id）;
$ this-> db-> limit（1）;
$ this-> db-> delete（'my_table'）;
详细说明如下：
http://www.codeigniter.com/userguide3/database/query_builder.html#deleting-data
要编辑数据，您将收集表单输入，因此：
http://www.codeigniter.com/userguide3/libraries/input.html
使用您的错误检查输入值，使用查询构建器（链接到前面）将新数据发布到数据库。
p>
$ data = array（
'name'=> $ name，
'description'=> $ description;
）;
$ this-db-where（'question_id'，$ question_id）;
$ this-> db-> update（'mytable'，$ data）;
我希望以某种方式帮助，如果没有，请在您的问题中更具体。 / p>
您的网站很好运，
最好的祝福，
保罗
I am having trouble coding to edit/delete a question in the database. From my quiz questions. This is my model. I would like to edit a question from the view through the controller.
This is my current mode:
function getquestions($quizid)
{
// get data about the quiz - we need the quiz size
$quiz = $this->getquiz($quizid);
$qzsize = $quiz['quizsize'];
$this->db->select('id'); // we want just the id fields
$this->db->limit($qzsize); // how many questions to ask
// this next clause allows us to select random questions - a full discussion of how this works and its drawbacks is
// here https://www.warpconduit.net/2011/03/23/selecting-a-random-record-using-mysql-benchmark-results/
$this->db->order_by('RAND()');
$res = $this->db->get_where('questions',array('quizid' => $quizid));
log_message('DEBUG',$this->db->last_query());
if ($res->num_rows() == 0) {
// no questions found!
// returning false to controller tells it we have encountered an error
// leave controller to decide how to handle error
return false;
}
$questions = array();
foreach ($res->result_array() as $row) {
$questions[] = $row['id'];
}
shuffle($questions); // provide questions in random order
$res->free_result();
return $questions;
}
/**
* get a question
* @param int - question id
* @return mixed false|array - question data + answers (array)
*/
function getquestion($id) {
$this->db->where('id',$id);
$res = $this->db->get('questions');
if ($res->num_rows() != 1) {
return false;
}
$question = $res->row_array(); // get first row as an array - this is the question data
// now get the answers for this question
$res = $this->db->get_where('answers',array('questionid' => $id));
if ($res->num_rows() < 2) {
// must have at least two answers
return false;
}
$answers = array();
// get each row as an array and push it onto the answers array
foreach ($res->result_array() as $row) {
$answers[] = $row;
}
shuffle($answers);
// now return all the data as one array, with keys to help access elements
return array('q' => $question,'a' => $answers);
}
Somewhere in you controller you need to detect the 'delete' action. This might be through a URL or through a form input. I am sure you can do this bit.
For instance, a controller might have its method defined as
public function view($question_id=0, $action='') {
Then you might have a link on your page that has the action part defined as 'delete'. In you controller you would have an
if ($action == 'delete') {
To delete the chosen question from the database you would use
$this-db-where('question_id', $question_id);
$this->db->limit(1);
$this->db->delete('my_table');
Which is described in detail here: http://www.codeigniter.com/userguide3/database/query_builder.html#deleting-data
To edit the data, you would collect your form input thus:
http://www.codeigniter.com/userguide3/libraries/input.html
And using your error checked input values, post the new data to your database using the query builder (linked to earlier).
Something like
$data = array(
'name' => $name,
'description' => $description;
);
$this-db-where('question_id', $question_id);
$this->db->update('mytable', $data);
I hope that helps in some way, or if not, please be more specific in your question.
Good luck with your website,
Best wishes,
Paul
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