從數據庫中提取數據。 如何編寫循環 function PHP MYSQL

Question

問題如下。 我有兩個表用戶和卡。 當用戶有兩張或更多卡時，如何編寫循環 function？ 示例：用戶 bane 有卡片 222222 和 454545。但是，當我向搜索字段發送問題時，它只會拋出第一張卡片。

<?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

您正在返回一個值。 如果我必須顯示所有用戶卡，我會做這樣的事情。

<?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']; 
} 
?>

這應該為每張卡片打印一行。

您還可以更改類似這樣的 where 子句以查找部分字符串：

users.first_name LIKE '%$search%' 

但是，如果您希望能夠搜索卡號並找到其所有者的所有關聯卡，那么您必須采取一些額外的步驟。

我會為這樣的事情 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

我嵌套了一個 select 來查找卡所有者，然后獲取所有關聯的卡。