php mysql插入具有唯一id的报告

Question

我正在尝试使用唯一的 ID 将新条目插入到我的数据库中。我的代码中的某个地方有错误，但我找不到它。你能帮忙吗？

自动增量不是选项

    $newConversationID = uniqid();

    $checkID = $DBcon->query("SELECT * FROM tbl_conversations WHERE conversation_id=$newConversationID");
    $countID = $checkID->num_rows;


    while($countID) {

        if ($countID==0) {
            $DBcon->query("INSERT INTO tbl_conversations (conversation_id,user_id, date) VALUES('$newConversationID','$fromID',UNIX_TIMESTAMP())");break;
        } else {

            $newConversationID = uniqid();

            $checkID = $DBcon->query("SELECT * FROM tbl_conversations WHERE conversation_id=$newConversationID");
            $countID = $checkID->num_rows;

        }

    }

Answer 1

是的，错误出现在 where($countId) 中。假设您没有使用该键找到相似的行，您将在 $countId 中得到零，零等于 FALSE。所以 where 子句永远不会运行。

因此，如果新的 uniqueid 与该表中的任何现有键都不匹配，则 while 循环将不会运行!

如果新的 uniqueid 确实与现有行匹配，则 while 循环将运行，但只会执行 ELSE 条件，这实际上不会做任何有用的事情。

I am assuming you want to loop until you create a valid new uniqid and then store that row.

$qfind = "SELECT COUNT(conversion_id) FROM tbl_conversations WHERE conversion_id = ?";
$search = $mysqli->prepare($qfind);
$qinsert = "INSERT INTO tbl_conversations (conversion_id) VALUES(?)";
$insert = $mysqli->prepare($qinsert);

//loop till we end up with a new unique id
while(true) {
    $id = uniqid();
    $search->bind_param('s', $id);
    $search->execute();
    $result = $search->get_result();
    $row = $result->fetch_array(MYSQLI_NUM);

    if ($row[0] == 0) {
        // we have a new unique index so store the row
        $insert->bind_param('s', $id);
        $insert->execute();

        // we are all done here so break out of the while loop
        break;
    }
}