从数据库中提取数据。 如何编写循环 function PHP MYSQL

Question

问题如下。 我有两个表用户和卡。 当用户有两张或更多卡时，如何编写循环 function？ 示例：用户 bane 有卡片 222222 和 454545。但是，当我向搜索字段发送问题时，它只会抛出第一张卡片。

<?php 
    require "connection.php";
    $search = $_POST['search'];

    $sql = "SELECT users.first_name, users.second_name, cards.card_number
            FROM users
            INNER JOIN cards
            ON cards.user_id = users.id
            WHERE cards.card_number = '$search'
            OR users.first_name = '$search'
            OR users.second_name = '$search'";

    $query = mysqli_query($db, $sql);
    $result = mysqli_fetch_assoc($query);

    echo $result['first_name']." ".$result['second_name']." ",
    $result['card_number']; ?>

https://i.stack.imgur.com/0VvXF.jpg

Answer 1

跑

$results = mysqli_fetch_assoc($query);

foreach( $results as $result) {
    echo .....
}

Answer 2

您正在返回一个值。 如果我必须显示所有用户卡，我会做这样的事情。

<?php 
    require "connection.php";
    $search = $_POST['search'];

    $sql = "SELECT users.first_name, users.second_name, cards.card_number
            FROM users
            INNER JOIN cards
            ON cards.user_id = users.id
            WHERE
            users.first_name = '$search'
            OR users.second_name = '$search'";

    $query = mysqli_query($db, $sql);
while ($row = mysqli_fetch_assoc($query)) {

    echo $row['first_name']." ".$row['second_name']." ",
    $row['card_number']; 
} 
?>

这应该为每张卡片打印一行。

您还可以更改类似这样的 where 子句以查找部分字符串：

users.first_name LIKE '%$search%' 

但是，如果您希望能够搜索卡号并找到其所有者的所有关联卡，那么您必须采取一些额外的步骤。

我会为这样的事情 go ：

 SELECT t1.customerIDi, cards.number, customer.* 
 FROM CARDS
 LEFT JOIN customer ON cards.CustomerID = customer.id
 INNER JOIN (
     SELECT customer.id AS customerIDi
     FROM customer
     LEFT JOIN cards
     ON cards.CustomerID = customer.id
     WHERE
     Cards.Number = "$search"
 ) AS t1
 ON t1.customerIDi = cards.CustomerID

http://sqlfiddle.com/#!9/82ad8/23/0

我嵌套了一个 select 来查找卡所有者，然后获取所有关联的卡。