因此，我必须创建一个网上商店，一个人可以在其中过滤产品。 我添加了[pod 300€]和[vsi izdelki]按钮。但是现在当我 单击按钮[pod 300€]，它会显示价格低于300€的商品，但同时还会显示下方的所有商品。我如何解决该问题 点击[pod 300€]，它仅显示300€以下的产品。
<?php
include "header.php";
$connect = mysqli_connect("localhost", "root", "", "registration");
if(isset($_POST["add_to_cart"]))
{
if(isset($_SESSION["shopping_cart"]))
{
$item_array_id = array_column($_SESSION["shopping_cart"], "item_id");
if(!in_array($_GET["id"], $item_array_id))
{
$count = count($_SESSION["shopping_cart"]);
$item_array = array(
'item_id' => $_GET["id"],
'item_name' => $_POST["hidden_name"],
'item_price' => $_POST["hidden_price"],
'item_quantity' => $_POST["quantity"]
);
$_SESSION["shopping_cart"][$count] = $item_array;
}
else
{
echo '<script>alert("Izdelek je že bil dodan")</script>';
}
}
else
{
$item_array = array(
'item_id' => $_GET["id"],
'item_name' => $_POST["hidden_name"],
'item_price' => $_POST["hidden_price"],
'item_quantity' => $_POST["quantity"]
);
$_SESSION["shopping_cart"][0] = $item_array;
}
}
if(isset($_GET["action"]))
{
if($_GET["action"] == "delete")
{
foreach($_SESSION["shopping_cart"] as $keys => $values)
{
if($values["item_id"] == $_GET["id"])
{
unset($_SESSION["shopping_cart"][$keys]);
echo '<script>alert("Izdelek odstranjen")</script>';
echo '<script>window.location="kosarica.php"</script>';
}
}
}
}
?>
<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.0/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
</head>
<body>
<br />
<div class="container">
<br />
<br />
<br />
<br /><br />
<?php
$connect = mysqli_connect("localhost", "root", "", "registration");
if(isset($_POST["manj300"])){
$query =mysqli_query($connect, "SELECT * FROM tbl_product WHERE price<=300");
while($row=mysqli_fetch_array($query)){
?>
<div class="col-md-4">
<form method="post" action="produkti.php?action=add&id=<?php echo $row["id"]; ?>">
<div style="border:1px solid #333; background-color:#f1f1f1; border-radius:5px; padding:16px;" align="center">
<img src="slike/<?php echo $row["image"]; ?>" class="img-responsive" /><br />
<h4 class="text-info"><?php echo $row["name"]; ?></h4>
<h4 class="text-danger">€ <?php echo $row["price"]; ?></h4>
<input type="text" name="quantity" value="1" class="form-control" />
<input type="hidden" name="hidden_name" value="<?php echo $row["name"]; ?>" />
<input type="hidden" name="hidden_price" value="<?php echo $row["price"]; ?>" />
<input type="submit" name="add_to_cart" style="margin-top:5px;" class="btn btn-success" value="Dodaj v košarico" />
</div>
</form>
</div>
<?php
}
}
?>
<?php
$connect = mysqli_connect("localhost", "root", "", "registration");
if(isset($_POST["vsi_izdelki"])){
$query =mysqli_query($connect, "SELECT * FROM tbl_product");
while($row=mysqli_fetch_array($query)){
?>
<div class="col-md-4">
<form method="post" action="produkti.php?action=add&id=<?php echo $row["id"]; ?>">
<div style="border:1px solid #333; background-color:#f1f1f1; border-radius:5px; padding:16px;" align="center">
<img src="slike/<?php echo $row["image"]; ?>" class="img-responsive" /><br />
<h4 class="text-info"><?php echo $row["name"]; ?></h4>
<h4 class="text-danger">€ <?php echo $row["price"]; ?></h4>
</div>
</form>
</div>
<?php
}
}
?>
<form method="post" action="produkti.php">
<input type="submit" name="manj300" style="margin-top:5px;" class="btn btn-success" value="pod 300€" />
<input type="submit" name="vsi_izdelki" style="margin-top:5px;" class="btn btn-success" value="vsi izdelki" />
</form>
<?php
$query = "SELECT * FROM tbl_product ORDER BY id ASC";
$result = mysqli_query($connect, $query);
if(mysqli_num_rows($result) > 0)
{
while($row = mysqli_fetch_array($result))
{
?>
<div class="col-md-4">
<form method="post" action="produkti.php?action=add&id=<?php echo $row["id"]; ?>">
<div style="border:1px solid #333; background-color:#f1f1f1; border-radius:5px; padding:16px;" align="center">
<img src="slike/<?php echo $row["image"]; ?>" class="img-responsive" /><br />
<h4 class="text-info"><?php echo $row["name"]; ?></h4>
<h4 class="text-danger">€ <?php echo $row["price"]; ?></h4>
<input type="text" name="quantity" value="1" class="form-control" />
<input type="hidden" name="hidden_name" value="<?php echo $row["name"]; ?>" />
<input type="hidden" name="hidden_price" value="<?php echo $row["price"]; ?>" />
<input type="submit" name="add_to_cart" style="margin-top:5px;" class="btn btn-success" value="Dodaj v košarico" />
</div>
</form>
</div>
<?php
}
}
?>
<div style="clear:both"></div>
<br />
</div>
</div>
<br />
</body>
</html>
<?php
include "footer.php";
?>
答案 0 :(得分：1)
问题是，如果获得过滤器，则会使用正确的过滤器进行db-request，但是之后，您仍将使用默认的db-request来获取所有产品。
不要发出多个数据库请求，而只需发出一个。您可以根据从客户端获得的过滤器来更改查询。
类似这样的东西：
$whereConditions = [];
$where = '';
if (isset($_POST["manj300"])) {
// Add this filter
$whereConditions[] = 'price<=300';
}
// Here you can add more conditions, just like the above if-statement
if ($whereConditions) {
// We have a condition, implode and add WHERE
$where = 'WHERE ' . implode(' ', $whereConditions);
}
// Now put the where conditions in your query
$query = "SELECT * FROM tbl_product {$where} ORDER BY id ASC";
$result = mysqli_query($connect, $query);
if(mysqli_num_rows($result) > 0)
{
while($row = mysqli_fetch_array($result))
{
// Your current code
}
}
?>
此方法的好处是您可以轻松地在同一查询中添加更多条件/过滤器。
缺点是代码变得更难阅读。
您可以定义多个查询，然后选择要使用的查询：
// This is the "get all" query
$query = "SELECT * FROM tbl_product ORDER BY id ASC";
if (isset($_POST["manj300"])) {
// We have a filter, let's override the default query
$query = "SELECT * FROM tbl_product price<=300 ORDER BY id ASC";
}
$result = mysqli_query($connect, $query);
if(mysqli_num_rows($result) > 0)
{
while($row = mysqli_fetch_array($result))
{
// Your current code
}
}
?>
此方法的好处是它非常干净，易于阅读和遵循。
缺点是您只能同时启用一个过滤器。