php - MySQL WHERE something = $something 和 $something = 默认情况下的每个值

Question

我正在尝试为我的网上商店做一个过滤器。我有以下查询

$column = mysqli_query($link, "SELECT brand FROM shields WHERE
brand=".$brand." ORDER BY id DESC LIMIT ".$offset. "," . $itemsPerPage);

我希望默认情况下 $brand 等于 1、2 和 3 以显示每个项目在我的商店中，当我过滤时，它会将 $brand 更改为 1、2 或 3代码

$brand = filter_input(INPUT_GET, 'brand', FILTER_VALIDATE_INT);

Answer 1

你可以这样制作:

if(isset($_POST["brand"])){
  $brand = $_POST["brand"]; // filter_input(INPUT_GET, 'brand', FILTER_VALIDATE_INT);
  $filterByBrand = "and brand =".$brand;
}
else{
  $brand = "1,2,3";
  $filterByBrand = "and brand in(".$brand.")";
}


$column = mysqli_query($link, "SELECT brand FROM shields WHERE 1=1 
".$filterByBrand." ORDER BY id DESC LIMIT ".$offset. "," . $itemsPerPage);