Codeigniter-更新查詢成功執行，但$ this-> db-> affected_rows（）返回false

Question

我正在基於Codeigniter的Web項目上工作，我需要從管理面板更新用戶。 如果更新的值與數據庫中已存在的值不同，則它可以正常工作。 問題是$this->db->affected_rows()如果值不同，則返回TRUE ，但如果值相同，則返回FALSE。

這是我的代碼：-

// $where contains the array for where clause
// $data contains the array of user's data which includes the updated value

$this->db
        ->where($where)
        ->update('users', $data);

if($this->db->affected_rows() == true)
{
    $response = array(
        'message' => "User edited successfully",
        'status' => true
    );
}
else
{
    // this else block always get executed if the updated value is equal to the value already exists in database. But in reality the record was updated successfully

    $response = array(
        'message' => "Unable to edit user",
        'status' => false
    );
}

return $response;

Answer 1

它將返回numeric值，不是true請使用if($this->db->affected_rows() > 0)請在此處閱讀文檔

Answer 2

您可以使用事務檢查查詢是否成功執行。 之后，您可以檢查$ this-> db-> affected_rows（）來查看管理員是否真的更新了用戶值，並相應地返回了消息。

更新的代碼：

$this->db->trans_start();

    // $where contains the array for where clause
    // $data contains the array of user's data which includes the updated value

    $this->db
            ->where($where)
            ->update('users', $data);

$this->db->trans_complete();        

if($this->db->trans_status() === FALSE)
{
    $response = array(
        'message' => "Unable to edit user",
        'status' => false
    );
}
else
{
    if($this->db->affected_rows() > 0)
    {
        $response = array(
            'message' => "User edited successfully",
            'status' => true
        );
    }
    else
    {
        $response = array(
            'message' => "User edited successfully, but it looks like you haven't updated anything!",
            'status' => true
        );
    }
}


return $response;

Answer 3

根據CI文檔， $this->db->affected_rows()如果用戶進行了任何編輯，則返回true；如果查詢成功執行但用戶未更改數據，則返回false。

您只需確認查詢已成功運行。如果查詢成功運行，則意味着您的數據已更新。

$result = $this->db
        ->where($where)
        ->update('users', $data);

if ( ! $result)
{
     // Error

}else{

     // Function ran ok - do whatever
         if($this->db->affected_rows() == true)
        {
            $response = array(
             'message' => "User edited successfully",
            'status' => true
             );
        } else {
          $response = array(
          'message' => "There is nothing to update",
           'status' => false
          );
     }

}