Php 我尝试在2个不同的SQL表上运行2个“while”循环

警告：mysql\u fetch\u数组期望参数1是资源，布尔值在第148行的C:\public\u html\mars\TaskC\hitUrl.php中给出

$query  = "SELECT url FROM urls";
$tableQuery = mysql_query($query);


while($row = mysql_fetch_array($tableQuery)){
    $newQuery="SELECT urls,date FROM urls_info WHERE url='{$row['url']}'";
    $newTableQuery=mysql_query($newQuery);

    $newGroupedQuery = $newQuery . "GROUP BY date";

    while($newRow = mysql_fetch_array($newTableQuery)){
        $displayStr .=    "<tr>";
        $displayStr .=    "<td>".$newRow['date']."</td>";
        $displayStr .=    "<td>".$newRow['url']."</td>";
        $displayStr .=    "<td>".num_rows($newQuery)."</td>";
        $displayStr .=    "</tr>";   
    }


}

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看起来mysql_查询失败了， 试着放一些像这样的东西

$tableQuery = mysql_query($query) or die("Query failed with error: ".mysql_error());

而且SQL连接更适合本机操作，更注重性能

始终以本机方式加入：

$newQuery="SELECT urls,date FROM urls_info as info INNER JOIN urls ON info.url = urls.url";

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为什么不使用联接执行单个查询呢？