如果某些条件，如何使复选框被选中

Question

我必须向学生展示复选框，如果有明确的老师教这些学生，他们必须被检查。如果这些学生不是他的学生，那就不用查了。我有两个查询来计算 2 个值，但在我的情况下，当它们相等时，不会在 ckechboxes 中检查学生，而是写成：checked="checked" > >。以及如何关闭我的复选框，在学生姓名前显示> > >。

我的看法是：

<?php
foreach($select_students as $student) 
{
 
?>
  
    <tr><td class='col-md-2'>

    <input type="checkbox" name="student[]"  value="<?php echo $student->user_id; ?>"  
    <?php  foreach($select_teachers_students as $select) {
      echo $student->user_id == $select->student_id ?  'checked="checked"' : ''
      ; ?> >
    

  <?php } 

    echo $student->username; ?>
  
    </td><td>

我的模型是：

public function select_students() {
  
        $this->db->select('users.user_id, users.username, users.school_id, users.class, users.division, users.role_id, schools.school_name, schools.region,class_divisions.division');
        $this->db->from('users');
        $this->db->join('class_divisions','class_divisions.id=users.division','left');
        $this->db->join('schools','schools.school_id=users.school_id','left');
        $this->db->where('(users.deactivated_at = "0000-00-00 00:00:00" OR users.deactivated_at IS NULL) AND users.role_id = 1 ');
        $this->db->where('users.school_id',$this->uri->segment(4) );
        $result=$this->db->get();
            return $result->result();
 }


public function edit_students() {
     
        $submit=$this->input->post('change');
        $date = new DateTime("now"); 
        if(isset($submit)&&($submit=='Промени ученици')) {
          if($this->input->post('student')) {
          foreach($this->input->post('student') AS $student) {
          $data = array(         
            'student_id' => $student,
            // 'teacher_id' => $this->uri->segment(3),
             'created_at' => $date->format('Y-m-d H:i:s')         
          );
          $this->db->where('teacher_id',$this->uri->segment(3));
          $this->db->update('teacher_student_conn', $data);    
      
            if($this->db->affected_rows() > 0)
            {   
                return true;
            } 

              return false;
            }
          }
      }

    }

我的控制器是：

  public function edit_students()
    {
        if($this->admin_model->edit_students()) {
            echo "Tou changed teacher successfully!";
            $teacher_id = $this->uri->segment(3);
			$school_id = $this->uri->segment(4);
            header('Refresh: 2; url=/survey/index.php/admin/edit_students/'.$teacher_id .'/' .$school_id);
        }
        else
        { 
           
            $data['dynamic_view'] = 'edit_students'; 
            $data['select_students']=$this->admin_model->select_students();
            $data['select_teachers_students']=$this->admin_model->select_teachers_students();
            $data['teacher_name']=$this->admin_model->teacher_name();
            $data['menu']=$this->menu_model->get_menu();
            $this->load->view('templates/main',$data);
        }
    }

现在我编辑了我的模型，它是：

public function select_teachers_students() {
      $this->db->select('*');
      $this->db->from('teacher_student_conn');
      $this->db->where('teacher_student_conn.teacher_id',$this->uri->segment(3) );
      $result=$this->db->get();
            return $result->result();
 }
public function edit_students() {
     
        $submit=$this->input->post('change');
        $date = new DateTime("now"); 
        if(isset($submit)&&($submit=='Промени ученици')) {
          if($this->input->post('student')) {
           foreach($this->input->post('student') AS $student) {
            if($this->input->post('student')==$this->select_teachers_students()) {
             
          $data = array(         
            'student_id' => $student,
            
             'created_at' => $date->format('Y-m-d H:i:s')         
          );
          $this->db->where('teacher_id',$this->uri->segment(3));
          $this->db->update('teacher_student_conn', $data);    
      
    }
      else if($this->input->post('student')!=$this->select_teachers_students()) {
        
         $data = array(         
            'student_id' => $student,
             'teacher_id' => $this->uri->segment(3),
             'created_at' => $date->format('Y-m-d H:i:s')         
          );
         $this->db->insert('teacher_student_conn', $data);   
      }
      }
            if($this->db->affected_rows() > 0)
            {   
                return true;
            } 

              return false;
            }
          }
      

    }

但插入我已经拥有的行。我尝试使用函数 select_teachers_students() 进行检查，如果它们在那里，我不想再次插入 - 我想更新它们。以及如何在选中复选框时设置复选框的值，插入value="<?php echo $student->user_id; ?>" 但是，当未选中复选框并且我按下提交按钮时，插入Value='0'。如果它们不存在，我想插入。

Answer 1

你们之间似乎多了一个>

?> >      

  <?php

标签。由于这是在 foreach 循环中，因此它将被执行多次。

更严肃的一点是，您的视图逻辑需要改头换面。使用 Smarty 之类的模板引擎。

Answer 2

用于输出复选框的代码似乎不正确。请尝试以下操作：

<td class='col-md-2'>
    <input type="checkbox" name="student[]"  value="<?php echo $student->user_id; ?>"
    <?php foreach($select_teachers_students as $select) { ?>
          <?php echo $student->user_id == $select->student_id ? 'checked="checked"' : ''; ?>            
    <?php } ?>  
    />
    <?php echo $student->username; ?>
</td>

这应该可行。在您的情况下，循环设置不正确...

Answer 3

而不是使用：

<?php  foreach($select_teachers_students as $select) {
      echo $student->user_id == $select->student_id ?  'checked="checked"' : ''
      ; ?> >

您应该使用 in_array 函数来检查老师是否教过任何学生。 示例：

select_teachers_students=array(12, 34, 25);// Student ids array 
if(in_array($student,select_teachers_students){
     echo "checked='checked'";
}

因为错误，最后加了一个>。

Answer 4

每个input 元素只需要一个checked="checked"。然后，首先计算是否检查了学生，然后（何时构建输出）使用它。

<?php
foreach ( $select_students as $student ) {
    $checked = false;
    foreach ( $select_teachers_students as $select ) {
        if ( $student->user_id == $select->student_id ) {
            $checked = true;
            break;
        }
    }
    printf( '<tr><td class="col-md-2">'
            . '<input type="checkbox" name="student[]" value="%s" %s />'
            . '</td><td>%s</td></tr>',
            $student->user_id,
            $checked ? 'checked="checked"' : '',
            $student->username );
}
?>