如何使用php在sql的两个表中获取特定用户的数据。

Question

从两个表中获取数据已经开始工作，但是我不知道如何从两个表中获取用户的特定数据。我不知道把这段代码放在哪里//哪里seller_id= '“.$_SESSION‘卖家_id’. "‘")；

下面是我的代码：

<?php
$seller_id = $_SESSION['seller_id'];
$user_query = mysqli_query($db, "SELECT seller.s_fname, seller.s_lname, seller.trade_name, seller.s_address, selling_details.opening_time, selling_details.opening_days, selling_details.order_cutoff, selling_details.seller_delivery_time, selling_details.area_covered_delivery, selling_details.delivery_fee FROM seller INNER JOIN selling_details ON seller.seller_id=selling_details.seller_id
WHERE seller.seller_id=selling_details.seller_id");
$seller = mysqli_fetch_assoc($user_query);
?>

Answer 1

由于您需要在into查询中嵌入一些参数，因此我们将使用prepared statements来防止SQL injection攻击。

// Get seller ID
$seller_id = $_SESSION['seller_id'];

// Prepare the query that will be executed
$stmt = $db->prepare("SELECT seller.s_fname AS s_fname, seller.s_lname AS s_lname, seller.trade_name AS trade_name, seller.s_address AS s_address, selling_details.opening_time AS opening_time, selling_details.opening_days AS opening_days, selling_details.order_cutoff AS order_cutoff, selling_details.seller_delivery_time AS seller_delivery_time, selling_details.area_covered_delivery AS area_covered_delivery, selling_details.delivery_fee AS delivery_fee FROM seller INNER JOIN selling_details ON seller.seller_id=selling_details.seller_id WHERE seller.seller_id = ?");

// Instead of that '?', put the $seller_id
$stmt->bind_param('i', $seller_id);

// Execute the statement.
$stmt->execute();

// Get the results.
$result = $stmt->get_result(); 

// For each row, get it's associative array representation.
while ($row = mysqli_fetch_assoc($result)) {
    // Echo first and last name.
    echo $row['s_fname'].' '.$row['s_lname'].'<br/>';
}

// Close the statement.
$stmt->close();

Answer 2

<?php
$seller_id = $_SESSION['seller_id'];
$user_query = mysqli_query($db, "SELECT seller.s_fname, seller.s_lname, seller.trade_name, seller.s_address, selling_details.opening_time, selling_details.opening_days, selling_details.order_cutoff, selling_details.seller_delivery_time, selling_details.area_covered_delivery, selling_details.delivery_fee FROM seller INNER JOIN selling_details ON seller.seller_id=selling_details.seller_id
WHERE seller.id=$seller_id");
$seller = mysqli_fetch_assoc($user_query);
?>