Question

即使未删除该项，deleteItem方法也会返回true。如果没有对数据库进行任何更改，如何在此特定情况下使用$mysqli->affected_rows来检查并返回false？

public function deleteItem($item_id)
{
    $userItemIDS = array();

    $userItemIDS = $this->helperClass->userItemIDS();

    $q = $this->db->mysqli->prepare("DELETE i, s FROM items i
    LEFT JOIN save_list s
        ON i.id = s.item_id
        WHERE i.id = ? AND s.item_id = ?
    AND
        NOT EXISTS (SELECT id FROM pending_wins WHERE item_id = ?)
    AND
        NOT EXISTS (SELECT id FROM bids WHERE item_id = ?)");

    if( $q != false && in_array($item_id, $userItemIDS) )
    {
        $q->bind_param("iiii", $item_id, $item_id, $item_id, $item_id);
        $q->execute();
        $q->close();
        return true;
    }
        return false;
}

Answer 1

这就是必须的。

public function deleteItem($item_id)
{
    $userItemIDS = $this->helperClass->userItemIDS();
    if( !in_array($item_id, $userItemIDS) )
    {
        return FALSE;
    }
    $sql = "...";
    $q = $this->db->mysqli->prepare($sql);
    $q->bind_param("iiii", $item_id, $item_id, $item_id, $item_id);
    $q->execute();
    return (bool)$this->db->mysqli->affected_rows;
}

Answer 2

根据评论请求，伪代码：

if (ok to run query) {
   $q = "...build/prepare/bind query...";
   if ($q->execute() === false) {
       return false; // query failed
   } else {
       return $q->rowCount(); // return number of rows affected
   }
}

mysqli - 如何在0个受影响的行上返回false

2 个答案: