如何防止CodeIgniter中的重复记录 [英] How to prevent duplicate records in CodeIgniter

问题描述

我会选择的人然后在我的朋友数据库中出现两次.如何防止重复的条目进入这里?我尝试使用存在的sql命令，但是没有运气

The person I would have selected will then appears as twice in my friends database. How do I prevent a duplicate entry going in here? I have tried using exists sql command but no luck

朋友模型:

   function addFriend($username, $friendname)
 {
$record = array('username'=> $username,
                 'friend' => $friendname);

$this->db->insert('friends', $record);


 }


 function getFollowing($username)
{
$following = array();
$this->db->select('*')->from('friends')->where('username', $username);
$followingSet = $this->db->get();
foreach ($followingSet->result() as $row)
{
    if(isset($username)){

        $following[] = $row->friend;
    }
    else 
    {
        return false;


    }

}

return $following;
}

视图:

 <?php foreach($friends['following'] as $name):?>
        <li>  <?=anchor("profile/view/$name", $name)?>, (<?=anchor("home/drop/$name", 'drop')?>)</li>
      <?php endforeach?>=

我想做的就是停止重复的条目进入数据库-我将如何在sql语句中使用exist关键字?

The thing I want to do is stop duplicate entries going in my database - how would I use the exists keyword in my sql statement?

推荐答案

插入时，您可以调用 getFollowing 方法并执行以下操作:

When you insert you can call your getFollowing method and go like this:

function add_follower($username, $friend_username)
{
    $current_followers = $this->getFollowing($username);

    if(!in_array($friend_username, $current_followers)
    {
        // Add to followers
    }
 }

为此，您需要将 getFollowing 更改为此:

For this you need to change your getFollowing to this:

function getFollowing($username)
{
    $following = array();

    $this->db->select('*')->from('friends')->where('username', $username);

    $followingSet = $this->db->get();

    foreach ($followingSet->result() as $row)
    {
        $following[] = $row->friend;
    }
    return $following;
}

这可能不会100％正确，因为我不知道如何配置您的数据库/模型.但这应该使您对如何执行此操作有一个大致的认识

This will not work 100% right probably, because I have no idea how your database / models are configured. But it should give you a general idea on how to do this

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