PHP ページで 2 種類の MySQL 接続を使用することは可能ですか?
現在、PHP には2 つの別個のファイルを介してアクセスされる$link = mysql_connectおよび接続があります。$mysqli = new mysqliinclude
どちらも MySQL データベースからデータを取得しますが、両方が同じ PHP ページにある場合、2 番目の接続は機能しません。
本当に明らかな何かが欠けていますか?
mysql
$link = mysql_connect("localhost", "root", "root", "abc");
if(!$link)
{
    die('There was a problem connection to the database.  Please contact your survey administrator.');
}
mysql_select_db("root");
$query = "SELECT * FROM tresults";
$result = mysql_query($query);
$total = mysql_num_rows($result);
$query1 = "SELECT * FROM trespondent";
$result1 = mysql_query($query1);
$total1 = mysql_num_rows($result1) - 1;
    $percent = number_format(($total * 100) / $total1);
mysql_close($link);
}
みずい
$mysqli = new mysqli("localhost", "root", "root", "abc");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$a = 'q';
$aa = 1;
$r = "$a$aa";
$q = 55;
while($aa <= $q){
$query  .= "SELECT COUNT(". $r .") as Responses, (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = -1 ) as NA, (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 1 ) as SD, (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 2 ) as D, (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 3 ) as A, (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 4 ) as SA, ((SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 3 ) + (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 4)) as Pos, ((SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 1 ) + (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 2)) as Neg, (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." >= 1) AS Total, ( ((SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 3 ) + (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." = 4)) / (SELECT COUNT(". $r .") FROM tresults WHERE ". $r ." >= -1)  ) *100 AS percentage FROM tresults;";
$aa = $aa + 1;
$r = "$a$aa";
注: コードの残りの部分とクローズは、次を使用して PHP ページ内で処理されます。$mysqli->close();
if ($mysqli->multi_query($query)) {
                                $n = 0;
                                do {
                                    /* store first result set */
                                    if ($result = $mysqli->store_result()) {
                                        $i = 1;
                                        $p = 1;
                                        while ($row = $result->fetch_row()) {
                                            // print_r($row);
                                            $n++;
    
