php - 成功查询时出现 fetch_object() 错误

Question

我收到此错误:

Fatal error: Call to a member function fetch_object() on a non-object in C:\.....php on line 136

代码如下:

if ($result = $mysqli->query("INSERT INTO partlistlist ( P_fam , P_code , P_name, P_var , P_ver , P_lnk , P_fol , P_Notes , P_status , P_op ) VALUES ( \"".$mod_fam ."\", \"".$mod_code ."\", \"".$mod_name ."\", \"".$mod_var  ."\", 1 , \"".$mod_lnk  ."\", \"".$mod_fold ."\", \"".$mod_note     ."\", \"".$mod_stat ."\", \"".  $_SESSION['wh_pwd_usr']."\"  ) "));
{
    echo "<br>Articolo creato con successo";
    $created_id = $mysqli->insert_id;
    if (!$result = $mysqli->query("SELECT * FROM partlistlist WHERE P_id = $created_id LIMIT 1"))
        echo "Error";
    $row = $result->fetch_object();
    $P_id = $created_id;

    if (!$result_clonepart = $mysqli->query("SELECT * FROM partlist WHERE K_pid = $old_P_id"))
    {
        echo "Error";
    }
    else
    {
        if ($result_clonepart->num_rows > 0)
        {
            while ($row_clonepart = $result_clonepart->fetch_object())
            {
                if (!$result_clonepart = $mysqli->query("INSERT INTO partlist ( K_ref ,K_pid ,K_iid ,K_qty ,K_subpid, K_stat ) VALUES ( \"".$row_clonepart->K_ref      ."\" ,\"". $P_id    ."\" ,\"".$row_clonepart->K_iid     ."\" ,\"".$row_clonepart->K_qty     ."\" ,\"".$row_clonepart->K_subpid   ."\" ,\"".$row_clonepart->K_stat       ."\")"))
                    echo "Error";
            }


        }
    }
}

第 136 行是:

while ($row_clonepart = $result_clonepart->fetch_object())

如果 num_rows 检查良好，$result_clonepart 怎么可能不是一个对象？

Answer 1

在 while 循环中，您正在重新分配 $result_clonepart (您可能不想做的事情)。如果该查询失败，您的脚本将因 fatal error 而停止。

使用不同的变量名(如果您不想使用相同的变量名)或在失败时中断循环(如果您有意重新分配)

while ($row_clonepart = $result_clonepart->fetch_object()) {
  //     VVVVVVVVVVV     Here is the reassignment
  if (!$result_clonepart = $mysqli->query("INSERT INTO partlist ( K_ref ,K_pid ,K_iid ,K_qty ,K_subpid, K_stat ) VALUES ( \"".$row_clonepart->K_ref      ."\" ,\"". $P_id    ."\" ,\"".$row_clonepart->K_iid     ."\" ,\"".$row_clonepart->K_qty     ."\" ,\"".$row_clonepart->K_subpid   ."\" ,\"".$row_clonepart->K_stat       ."\")"))
      echo "Error";
      //You could insert a break statement if you are reassigning the variable intentionally
}