在使用控制器函数php添加之前检查数据库中是否存在名称

Question

我有两个函数：checkDatabase($name) 和 add。 第一个检查传递的名称是否已经在数据库中。下一个添加如果尚未在数据库中。这是我的代码：

public function checkDatabase($name) {
        $list = $this->data_model->getCommunityList();

        foreach ($list as $sites) {
            if ($sites->name == $name) {
                return $name;
            }
        }

        return false;       
}

public function add(){
        $names = $this->input->post('add-list');

        if ($names != '') {
            if (strpos($names, "\n") == TRUE ) { //newline found
                $names = $this->input->post('add-list');
                $namesArray = explode("\n", $names);

                foreach($namesArray as $name) {
                    $checker = "";
                    $checker = $this->checkDatabase($name);
                    if ($checker == $name) {
                        echo "<script type='text/javascript'>alert('A site in your list already exists. Duplicate sites are not allowed.');</script>";
                    }

                    else {
                        $this->data_model->addCommunity($name);
                    }
                }

                $this->index();
                redirect(base_url());
            }
         }
}

我的模特：

public function addCommunity($name){
        $names = $this->db->escape_str($name);

        $sql = "INSERT INTO community (name) VALUES ('$name');";

        $query = $this->db->query($sql);

        return $query;
}

我的桌子：

问题是我的函数仍然在数据库中添加名称，即使它已经存在。即使 SQL 表显示“唯一”，我的查询仍然接受我的输入。我的代码有什么问题？请帮忙！！！

Answer 1

仅当记录不存在时才尝试插入。您可以在插入模型之前检查它，而不是为此调用另一个函数。

public function addCommunity($name){
        $names = $this->db->escape_str($name);
        $checkquery=$this->db->query("select * from community where name='$name'");
        if($checkquery->num_rows()==0)   // if there is no such a row then insert
        {
          $sql = "INSERT INTO community (name) VALUES ('$name')";
          $query = $this->db->query($sql);
          return $query;
       }
}

Answer 2

请用这种方法试试

public function checkDatabase($name) {
    $this->db->select ( 'name' );
    $this->db->from ( 'community' );
    $this->db->like ( 'name', '$name' );

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

    if ($query->num_rows () == 1) {
        $row = $query->first_row ();
        return $row->name;
    } else {
        return false;
    }

    return false;
}