php - mysql_num_rows 给出意外的结果

Question

我有以下功能:

public function already_tweeted($tweet){
        return mysql_num_rows(mysql_query("SELECT * FROM `retweeted` WHERE `tweet`='$tweet'"));
    }

非常简单。它检查数据库中是否已存在推文。

该表有以下记录:

id  user    tweet
3       You should retweet this too
2       Retweet this

(用户暂时为空)

这段代码:

$db_reader = new database_reader;
$already_tweeted = $db_reader->already_tweeted($tweet);
print $tweet . ". Already: ";
var_dump((bool) $already_tweeted);
print "<br>";

给出以下输出:

You should retweet this too. Already: bool(false) 
Retweet this. Already: bool(true) 

我几乎被困在这里了。当我在 phpmyadmin 中运行 SELECT * FROM retweeted WHERE tweet='You should retweet this too' 时，我得到了 1 行。

Answer 1

检查$tweet中的值是多少

类似问题

• http://bytes.com/topic/php/answers/875805-mysql_num_rows-argument-not-being-recognized-any-help-would-appreciated

同时更改此行以确保安全

return mysql_num_rows(mysql_query("SELECT * FROM retweeted WHERE tweet ='{$tweet}'"));