mysql / php / codeigniter更新具有相同ID的多行

Question

我有这两个表：

questions            answers
+-----+---------+    +------+------+---------+
| id_q| question|    | id_q | id_a | answer  |
+=====+=========+    +======+======+=========+
|  1  |question1|    |   1  |   1  | answer1 |
+-----+---------+    +------+------+---------+
|  2  |question2|    |   1  |   2  | answer2 |
+-----+---------+    +------+------+---------+
                     |   1  |   3  | answer3 |
                     +------+------+---------+
                     |   1  |   4  | answer4 |
                     +------+------+---------+
                     |   2  |   5  | answer5 |
                     +------+------+---------+
                     |   2  |   6  | answer6 |
                     +------+------+---------+
                     |   2  |   7  | answer7 |
                     +------+------+---------+
                     |   2  |   8  | answer8 |
                     +------+------+---------+

我正在尝试制作一个更新表格，可以在其中更新每个问题的每个答案。 下面表格的图片（顶部的数字是选择的id_q）。

目前我所拥有的是：

this->db->SELECT('*');
this->db->FROM('answers');
this->db->WHERE('answers.id_q', $x); // $x -> variable that has the id o the selected question
this->db->UPDATE('answers', $data);

显然，这是在更新表上所有具有相同id_q的条目，结果是：

answers
+------+------+---------+
| id_q | id_a | answer  |
+======+======+=========+
|   1  |   1  | answer1 |
+------+------+---------+
|   1  |   2  | answer1 |
+------+------+---------+
|   1  |   3  | answer1 |
+------+------+---------+
|   1  |   4  | answer1 |
+------+------+---------+

我要结束的是：能够更新每个问题的每个答案。 已经尝试使用临时表，但没有成功。

编辑：我期望得到的是当我更新这样的答案时：

https://imgur.com/a/SPg81IA

要获得这样的数据库：

answers
+------+------+-------------+
| id_q | id_a |   answer    |
+======+======+=============+
|   1  |   1  | answerone   |
+------+------+-------------+
|   1  |   2  | answertwo   |
+------+------+-------------+
|   1  |   3  | answerthree |
+------+------+-------------+
|   1  |   4  | answerfour  |
+------+------+-------------+

但是目前，我用“ answerone”获得了所有四个字段。

Answer 1

据我了解您的问题。 我想你要

this->db->SELECT('*');
this->db->FROM('answers');
this->db->WHERE('answers.id_q', $x); // $x -> variable that has the id o the selected question
this->db->WHERE('answers.id_a', $rightAnswerId);
this->db->UPDATE('answers', $data);

Answer 2

首先在您的更新表格中

在视图文件中：

对于输入字段answer1，answer2等。

将输入字段的名称放在数组中：

<input type="text" name="answers[]" placeholder="Answer 1"/>
<input type="text" name="answers[]" placeholder="Answer 2"/>
<input type="text" name="answers[]" placeholder="Answer 3"/>
<input type="text" name="answers[]" placeholder="Answer 4"/>

在控制器端：您可以将这些字段捕获为：

$answers = $this->input->post('answers');
$update_data = array();
for($answers as $key => $value){
  $update_data['answer'] = $value;
  //This part now should be done in model side:
  $this->db->where('id_q',$id_q);
  $this->db->where('id_a',($key + 1));
  $this->db->update('answers', $update_data);
}

Answer 3

更新问题：

this->db->UPDATE('questions', array('question' => 'question_title'),array('id_q' => 1));

更新答案：-

首先删除问题ID 1的所有答案

$this->db->delete('answers',array('id_q' => 1));

然后重新插入问题编号为1的所有答案

<?php 

$answers = $this->input->post('answers');
$insert_data = array();
for($answers as $key => $value){
  $row['id_q'] = 1;
  $row['answer'] = $value;
  array_push($insert_data, $row);
}
if(!empty($insert_data)){
    $this->db->insert_batch('answers',$insert_data); // will insert multiple rows
}

?>

这将工作100％。