Question

我的第一个代码就是这个

$it= mysql_query("SELECT comp_specs.type FROM comp_specs INNER JOIN users ON comp_specs.id=users.specification_id WHERE users.workgroup_id=1 AND comp_specs.type=0", $connection);
 $it_num =mysql_num_rows($it);
 $arrastre= mysql_query("SELECT comp_specs.type FROM comp_specs INNER JOIN users ON comp_specs.id=users.specification_id WHERE users.workgroup_id=2 AND comp_specs.type=0", $connection);
 $arrastre_num =mysql_num_rows($arrastre);
 $clinic= mysql_query("SELECT comp_specs.type FROM comp_specs INNER JOIN users ON comp_specs.id=users.specification_id WHERE users.workgroup_id=3 AND comp_specs.type=0", $connection);
 $clinic_num =mysql_num_rows($clinic);
 $Admin= mysql_query("SELECT comp_specs.type FROM comp_specs INNER JOIN users ON comp_specs.id=users.specification_id WHERE users.workgroup_id=4 AND comp_specs.type=0", $connection);
 $Admin_num =mysql_num_rows($Admin);

这项工作很棒，但它花了很多行代码，所以我试着这样做

$field=array('$it', '$arrastre', '$clinic',  '$admin' );

foreach($field as $fields){
 $(fields)= mysql_query("SELECT comp_specs.type FROM comp_specs INNER JOIN users ON comp_specs.id=users.specification_id WHERE users.workgroup_id=1 AND comp_specs.type=0", $connection);
 $(fields)_num =mysql_num_rows($fields);
}

但是发生了错误。

我需要一些关于如何使用foreach循环多次查询的帮助

Answer 1

尝试从$(fields)删除括号到$fields并停止使用mysql_*，因为它在PHP 7中不再存在

根据PHP的版本，有两个或三个PHP 用于访问MySQL数据库的API。 PHP 5用户可以选择不推荐使用的mysql扩展，mysqli或PDO_MySQL。 PHP 7删除 mysql扩展，只留下后两个选项。

Source

Answer 2

用于此程序

$sql = "SELECT id, firstname, lastname FROM MyGuests";
    $result = $conn->query($sql);

    if ($result->num_rows > 0) {
        // output data of each row
        while($row = $result->fetch_assoc()) {
            echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
        }
    } else {
        echo "0 results";
    }
    $conn->close();

用于mysql查询的循环

2 个答案: